data/hplc.jsonl

{"instruction": "Fix peak tailing/broadening/splitting.", "input": "Matrix: river water; Analytes: azo dyes; Column: C18, 2.1×100 mm, 1.7 µm; Oven 25°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Gradient 10→95% B over 6 min; Flow 0.30 mL/min. Observation: tailing factor ~1.8; occasional split peaks on main analyte.", "output": "Likely causes and actions:\n1) Match sample solvent to initial mobile phase; dilute strong solvents.\n2) Lower pH to suppress ionization for bases (pH 2.8–3.2) or raise for acids (pH 6.5–7.5).\n3) Consider polar-embedded/C18-AQ or PFP to reduce secondary interactions.\n4) Replace guard; check for column void (reverse flush briefly).\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "peak_shape", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Reduce carryover observed in blanks after high standards.", "input": "Matrix: QC standard in water; Analytes: azo dyes; Column: C18, 2.1×100 mm, 1.7 µm; Oven 45°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Isocratic 50% B; Flow 0.50 mL/min. Observation: blank after high standard shows 0.5–2% residual peak.", "output": "Likely causes and actions:\n1) Strengthen needle wash (≥80% organic + 0.1% acid); extend wash cycles.\n2) Include a high-organic purge step between runs; evaluate backflush if available.\n3) Use low-adsorption vials/caps; check sample loop/syringe cleanliness.\n4) Set acceptance carryover <0.1% of high standard peak area.\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "carryover", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Diagnose column frit clogging or void formation.", "input": "Matrix: serum; Analytes: sugars; Column: C8, 4.6×100 mm, 3.5 µm; Oven 35°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Gradient 10→80% B over 6 min; Flow 0.50 mL/min. Observation: plate count dropped 40%; asymmetry 1.7; possible void.", "output": "Likely causes and actions:\n1) Check asymmetry and plates with a system suitability compound.\n2) Reverse-flush 5–10 min; replace guard; inspect for voids (shoulder/doublet).\n3) Reduce max pressure; verify fittings/ferrules to prevent channeling.\n4) Log column volumes; retire if performance out of spec.\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "column_health", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Diagnose bubble/degassing issues causing ripple.", "input": "Matrix: wastewater effluent; Analytes: acidic herbicides (pKa 2–4); Column: PFP, 2.1×100 mm, 1.9 µm; Oven 30°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Isocratic 50% B; Flow 0.50 mL/min. Observation: periodic bubble bursts; UV shows spikes.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "degassing", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Diagnose bubble/degassing issues causing ripple.", "input": "Matrix: wine; Analytes: quinolones; Column: Phenyl-hexyl, 3.0×100 mm, 3 µm; Oven 35°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Gradient 10→60% B over 15 min; Flow 0.30 mL/min. Observation: periodic bubble bursts; UV shows spikes.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "degassing", "detector": "FLD", "instrument": "UHPLC"}}
{"instruction": "Fix peak tailing/broadening/splitting.", "input": "Matrix: urine; Analytes: azo dyes; Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 25°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 35% B; Flow 0.50 mL/min. Observation: tailing factor ~1.8; occasional split peaks on main analyte.", "output": "Likely causes and actions:\n1) Match sample solvent to initial mobile phase; dilute strong solvents.\n2) Lower pH to suppress ionization for bases (pH 2.8–3.2) or raise for acids (pH 6.5–7.5).\n3) Consider polar-embedded/C18-AQ or PFP to reduce secondary interactions.\n4) Replace guard; check for column void (reverse flush briefly).\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "peak_shape", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Fix peak tailing/broadening/splitting.", "input": "Matrix: tablet dissolution (pH 6.8); Analytes: phenols; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 30°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Isocratic 50% B; Flow 0.50 mL/min. Observation: tailing factor ~1.8; occasional split peaks on main analyte.", "output": "Likely causes and actions:\n1) Match sample solvent to initial mobile phase; dilute strong solvents.\n2) Lower pH to suppress ionization for bases (pH 2.8–3.2) or raise for acids (pH 6.5–7.5).\n3) Consider polar-embedded/C18-AQ or PFP to reduce secondary interactions.\n4) Replace guard; check for column void (reverse flush briefly).\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "peak_shape", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Resolve pump pulsation/check valve problems.", "input": "Matrix: QC standard in water; Analytes: steroids; Column: Polar-embedded C18, 2.1×150 mm, 3 µm; Oven 30°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Isocratic 50% B; Flow 1.0 mL/min. Observation: pulsation visible on pressure trace; peak area RSD ~6%.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "pump", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Resolve pump pulsation/check valve problems.", "input": "Matrix: cosmetics extract (IPA); Analytes: alkylbenzene sulfonates; Column: C18, 2.1×100 mm, 1.7 µm; Oven 35°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Gradient 2→95% B over 6 min; Flow 1.0 mL/min. Observation: pulsation visible on pressure trace; peak area RSD ~6%.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "pump", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Diagnose column frit clogging or void formation.", "input": "Matrix: milk; Analytes: beta-lactams; Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 45°C; A: water + 0.05% TFA; B: ACN; Gradient 10→80% B over 12 min; Flow 0.30 mL/min. Observation: plate count dropped 40%; asymmetry 1.7; possible void.", "output": "Likely causes and actions:\n1) Check asymmetry and plates with a system suitability compound.\n2) Reverse-flush 5–10 min; replace guard; inspect for voids (shoulder/doublet).\n3) Reduce max pressure; verify fittings/ferrules to prevent channeling.\n4) Log column volumes; retire if performance out of spec.\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "column_health", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Reduce carryover observed in blanks after high standards.", "input": "Matrix: milk; Analytes: acidic herbicides (pKa 2–4); Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 40°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Gradient 10→60% B over 8 min; Flow 0.30 mL/min. Observation: blank after high standard shows 0.5–2% residual peak.", "output": "Likely causes and actions:\n1) Strengthen needle wash (≥80% organic + 0.1% acid); extend wash cycles.\n2) Include a high-organic purge step between runs; evaluate backflush if available.\n3) Use low-adsorption vials/caps; check sample loop/syringe cleanliness.\n4) Set acceptance carryover <0.1% of high standard peak area.\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "carryover", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Diagnose retention time drift >5%.", "input": "Matrix: oil matrix (hexane); Analytes: polyphenols; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 35°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Gradient 10→95% B over 6 min; Flow 1.0 mL/min. Observation: RT drifts +6–10% over a batch of 30 samples.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "RT_drift", "detector": "MS", "instrument": "HPLC"}}
{"instruction": "Reduce carryover observed in blanks after high standards.", "input": "Matrix: drinking water; Analytes: acidic herbicides (pKa 2–4); Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 25°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Gradient 2→40% B over 10 min; Flow 0.40 mL/min. Observation: blank after high standard shows 0.5–2% residual peak.", "output": "Likely causes and actions:\n1) Strengthen needle wash (≥80% organic + 0.1% acid); extend wash cycles.\n2) Include a high-organic purge step between runs; evaluate backflush if available.\n3) Use low-adsorption vials/caps; check sample loop/syringe cleanliness.\n4) Set acceptance carryover <0.1% of high standard peak area.\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "carryover", "detector": "MS", "instrument": "HPLC"}}
{"instruction": "Stabilize noisy or drifting baseline.", "input": "Matrix: tablet dissolution (pH 6.8); Analytes: azo dyes; Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 40°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 50% B; Flow 1.0 mL/min. Observation: baseline ripple and drift during gradient; S/N reduced.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "baseline", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Troubleshoot high backpressure increase vs baseline.", "input": "Matrix: pharma API in diluent; Analytes: sugars; Column: C18, 2.1×100 mm, 1.7 µm; Oven 35°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Isocratic 60% B; Flow 0.30 mL/min. Observation: pressure increased 30–50% vs yesterday; pulses under gradient.", "output": "Likely causes and actions:\n1) Bypass column to assess system backpressure; replace inline filter and frits (0.2 µm).\n2) Flush column: 50:50 water:organic (10 min) → 100% organic (10 min) → 100% water (10 min).\n3) Check solvent miscibility; remove salts before 100% organic to avoid precipitation.\n4) Inspect pump seals/check valves; verify degasser performance (vacuum level OK).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "pressure", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Stabilize noisy or drifting baseline.", "input": "Matrix: soil extract (MeOH); Analytes: acidic herbicides (pKa 2–4); Column: PFP, 2.1×100 mm, 1.9 µm; Oven 45°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Gradient 2→40% B over 6 min; Flow 0.30 mL/min. Observation: baseline ripple and drift during gradient; S/N reduced.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "baseline", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Troubleshoot high backpressure increase vs baseline.", "input": "Matrix: tablet dissolution (pH 6.8); Analytes: beta-lactams; Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 25°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Isocratic 50% B; Flow 1.0 mL/min. Observation: pressure increased 30–50% vs yesterday; pulses under gradient.", "output": "Likely causes and actions:\n1) Bypass column to assess system backpressure; replace inline filter and frits (0.2 µm).\n2) Flush column: 50:50 water:organic (10 min) → 100% organic (10 min) → 100% water (10 min).\n3) Check solvent miscibility; remove salts before 100% organic to avoid precipitation.\n4) Inspect pump seals/check valves; verify degasser performance (vacuum level OK).\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "pressure", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Ensure sufficient column equilibration between runs.", "input": "Matrix: milk; Analytes: alkylbenzene sulfonates; Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 25°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Gradient 10→60% B over 6 min; Flow 1.0 mL/min. Observation: first run after gradient shift differs from subsequent runs.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "equilibration", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Diagnose column frit clogging or void formation.", "input": "Matrix: wastewater effluent; Analytes: steroids; Column: C18, 4.6×150 mm, 5 µm; Oven 30°C; A: water + 0.05% TFA; B: ACN; Isocratic 60% B; Flow 0.30 mL/min. Observation: plate count dropped 40%; asymmetry 1.7; possible void.", "output": "Likely causes and actions:\n1) Check asymmetry and plates with a system suitability compound.\n2) Reverse-flush 5–10 min; replace guard; inspect for voids (shoulder/doublet).\n3) Reduce max pressure; verify fittings/ferrules to prevent channeling.\n4) Log column volumes; retire if performance out of spec.\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "column_health", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Diagnose retention time drift >5%.", "input": "Matrix: serum; Analytes: sugars; Column: C8, 4.6×100 mm, 3.5 µm; Oven 35°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Gradient 5→40% B over 6 min; Flow 1.0 mL/min. Observation: RT drifts +6–10% over a batch of 30 samples.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "RT_drift", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: serum; Analytes: acidic herbicides (pKa 2–4); Column: PFP, 2.1×100 mm, 1.9 µm; Oven 35°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Gradient 2→95% B over 15 min; Flow 0.50 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "temperature", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Fix peak tailing/broadening/splitting.", "input": "Matrix: milk; Analytes: steroids; Column: C18, 4.6×150 mm, 5 µm; Oven 45°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Isocratic 35% B; Flow 0.40 mL/min. Observation: tailing factor ~1.8; occasional split peaks on main analyte.", "output": "Likely causes and actions:\n1) Match sample solvent to initial mobile phase; dilute strong solvents.\n2) Lower pH to suppress ionization for bases (pH 2.8–3.2) or raise for acids (pH 6.5–7.5).\n3) Consider polar-embedded/C18-AQ or PFP to reduce secondary interactions.\n4) Replace guard; check for column void (reverse flush briefly).\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "peak_shape", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Troubleshoot high backpressure increase vs baseline.", "input": "Matrix: urine; Analytes: acidic herbicides (pKa 2–4); Column: Polar-embedded C18, 2.1×150 mm, 3 µm; Oven 40°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Isocratic 35% B; Flow 0.50 mL/min. Observation: pressure increased 30–50% vs yesterday; pulses under gradient.", "output": "Likely causes and actions:\n1) Bypass column to assess system backpressure; replace inline filter and frits (0.2 µm).\n2) Flush column: 50:50 water:organic (10 min) → 100% organic (10 min) → 100% water (10 min).\n3) Check solvent miscibility; remove salts before 100% organic to avoid precipitation.\n4) Inspect pump seals/check valves; verify degasser performance (vacuum level OK).\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "pressure", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Reduce carryover observed in blanks after high standards.", "input": "Matrix: pharma API in diluent; Analytes: acidic herbicides (pKa 2–4); Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 30°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Gradient 5→60% B over 12 min; Flow 0.30 mL/min. Observation: blank after high standard shows 0.5–2% residual peak.", "output": "Likely causes and actions:\n1) Strengthen needle wash (≥80% organic + 0.1% acid); extend wash cycles.\n2) Include a high-organic purge step between runs; evaluate backflush if available.\n3) Use low-adsorption vials/caps; check sample loop/syringe cleanliness.\n4) Set acceptance carryover <0.1% of high standard peak area.\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "carryover", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Diagnose column frit clogging or void formation.", "input": "Matrix: wastewater influent; Analytes: steroids; Column: C8, 4.6×100 mm, 3.5 µm; Oven 45°C; A: water + 0.1% FA; B: ACN; Gradient 10→60% B over 8 min; Flow 1.0 mL/min. Observation: plate count dropped 40%; asymmetry 1.7; possible void.", "output": "Likely causes and actions:\n1) Check asymmetry and plates with a system suitability compound.\n2) Reverse-flush 5–10 min; replace guard; inspect for voids (shoulder/doublet).\n3) Reduce max pressure; verify fittings/ferrules to prevent channeling.\n4) Log column volumes; retire if performance out of spec.\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "column_health", "detector": "MS", "instrument": "HPLC"}}
{"instruction": "Ensure sufficient column equilibration between runs.", "input": "Matrix: drinking water; Analytes: azo dyes; Column: Phenyl-hexyl, 3.0×100 mm, 3 µm; Oven 30°C; A: water + 0.1% FA; B: ACN; Gradient 5→40% B over 12 min; Flow 0.30 mL/min. Observation: first run after gradient shift differs from subsequent runs.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "equilibration", "detector": "FLD", "instrument": "UHPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: wine; Analytes: basic amines (pKa 8–10); Column: PFP, 2.1×100 mm, 1.9 µm; Oven 30°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Isocratic 40% B; Flow 1.0 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "temperature", "detector": "MS", "instrument": "HPLC"}}
{"instruction": "Resolve buffer pH/precipitation/mixing problems.", "input": "Matrix: leaf extract; Analytes: phenols; Column: C8, 4.6×100 mm, 3.5 µm; Oven 45°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Isocratic 50% B; Flow 0.50 mL/min. Observation: salt precipitation suspected at high % organic.", "output": "Likely causes and actions:\n1) Use volatile buffers (ammonium formate/acetate) at ≤10–20 mM for MS; check pH at run temp.\n2) Avoid high-salt transitions to 100% organic; flush with salt-free aqueous before.\n3) Filter and degas buffers; replace after 48 h; verify miscibility A/B.\n4) At low pH for bases, add 0.1% FA; for strong tailing, consider 2–5 mM TFA (UV penalty).\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "buffer", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: food homogenate; Analytes: phenols; Column: C18, 4.6×150 mm, 5 µm; Oven 40°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Gradient 10→60% B over 10 min; Flow 0.30 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "temperature", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Stabilize noisy or drifting baseline.", "input": "Matrix: oil matrix (hexane); Analytes: vitamins (B-group); Column: C8, 4.6×100 mm, 3.5 µm; Oven 40°C; A: water + 0.1% FA; B: ACN; Gradient 5→80% B over 15 min; Flow 0.50 mL/min. Observation: baseline ripple and drift during gradient; S/N reduced.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "baseline", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: leaf extract; Analytes: basic amines (pKa 8–10); Column: Phenyl-hexyl, 3.0×100 mm, 3 µm; Oven 35°C; A: water + 0.1% FA; B: ACN; Isocratic 50% B; Flow 0.40 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "temperature", "detector": "FLD", "instrument": "UHPLC"}}
{"instruction": "Decide on ion-pairing conditions and caveats.", "input": "Matrix: QC standard in water; Analytes: polyphenols; Column: Polar-embedded C18, 2.1×150 mm, 3 µm; Oven 45°C; A: water + 0.05% TFA; B: ACN; Gradient 2→60% B over 20 min; Flow 0.50 mL/min. Observation: basic amines tail at pH>6; poor retention at low organic.", "output": "Likely causes and actions:\n1) Try without ion-pair first using acidic pH and endcapped C18; assess tailing.\n2) If needed, test HFBA/TFA (UV penalty) or volatile IP reagents for MS with caution.\n3) Document equilibration burden and memory effects; dedicate system if adopting IP.\n4) Consider polar-embedded or mixed-mode columns as alternatives.\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "ion_pair", "detector": "MS", "instrument": "HPLC"}}
{"instruction": "Stabilize noisy or drifting baseline.", "input": "Matrix: groundwater; Analytes: caffeine analogs; Column: C18, 2.1×100 mm, 1.7 µm; Oven 25°C; A: water + 0.05% TFA; B: ACN; Isocratic 50% B; Flow 1.0 mL/min. Observation: baseline ripple and drift during gradient; S/N reduced.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "baseline", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Decide on ion-pairing conditions and caveats.", "input": "Matrix: groundwater; Analytes: azo dyes; Column: C18, 2.1×100 mm, 1.7 µm; Oven 45°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Gradient 2→60% B over 6 min; Flow 1.0 mL/min. Observation: basic amines tail at pH>6; poor retention at low organic.", "output": "Likely causes and actions:\n1) Try without ion-pair first using acidic pH and endcapped C18; assess tailing.\n2) If needed, test HFBA/TFA (UV penalty) or volatile IP reagents for MS with caution.\n3) Document equilibration burden and memory effects; dedicate system if adopting IP.\n4) Consider polar-embedded or mixed-mode columns as alternatives.\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "ion_pair", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: QC standard in water; Analytes: glycosides; Column: C8, 4.6×100 mm, 3.5 µm; Oven 40°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Isocratic 40% B; Flow 1.0 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "temperature", "detector": "PDA", "instrument": "UHPLC"}}
{"instruction": "Stabilize noisy or drifting baseline.", "input": "Matrix: urine; Analytes: azo dyes; Column: Polar-embedded C18, 2.1×150 mm, 3 µm; Oven 35°C; A: water + 0.1% FA; B: ACN; Gradient 10→40% B over 8 min; Flow 0.50 mL/min. Observation: baseline ripple and drift during gradient; S/N reduced.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "baseline", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Diagnose column frit clogging or void formation.", "input": "Matrix: groundwater; Analytes: bile acids; Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 45°C; A: water + 0.1% FA; B: ACN; Isocratic 50% B; Flow 1.0 mL/min. Observation: plate count dropped 40%; asymmetry 1.7; possible void.", "output": "Likely causes and actions:\n1) Check asymmetry and plates with a system suitability compound.\n2) Reverse-flush 5–10 min; replace guard; inspect for voids (shoulder/doublet).\n3) Reduce max pressure; verify fittings/ferrules to prevent channeling.\n4) Log column volumes; retire if performance out of spec.\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "column_health", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Stabilize noisy or drifting baseline.", "input": "Matrix: drinking water; Analytes: amino acids; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 40°C; A: water + 0.1% FA; B: ACN; Isocratic 35% B; Flow 1.0 mL/min. Observation: baseline ripple and drift during gradient; S/N reduced.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "baseline", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Diagnose retention time drift >5%.", "input": "Matrix: drinking water; Analytes: beta-lactams; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 40°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Gradient 10→40% B over 12 min; Flow 0.40 mL/min. Observation: RT drifts +6–10% over a batch of 30 samples.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "RT_drift", "detector": "FLD", "instrument": "UHPLC"}}
{"instruction": "Reduce carryover observed in blanks after high standards.", "input": "Matrix: food homogenate; Analytes: neutral pesticides; Column: Phenyl-hexyl, 3.0×100 mm, 3 µm; Oven 40°C; A: water + 0.1% FA; B: ACN; Isocratic 40% B; Flow 0.50 mL/min. Observation: blank after high standard shows 0.5–2% residual peak.", "output": "Likely causes and actions:\n1) Strengthen needle wash (≥80% organic + 0.1% acid); extend wash cycles.\n2) Include a high-organic purge step between runs; evaluate backflush if available.\n3) Use low-adsorption vials/caps; check sample loop/syringe cleanliness.\n4) Set acceptance carryover <0.1% of high standard peak area.\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "carryover", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Ensure sufficient column equilibration between runs.", "input": "Matrix: urine; Analytes: neutral pesticides; Column: C18, 4.6×150 mm, 5 µm; Oven 30°C; A: water + 0.1% FA; B: ACN; Gradient 10→40% B over 6 min; Flow 0.30 mL/min. Observation: first run after gradient shift differs from subsequent runs.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "equilibration", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Decide on ion-pairing conditions and caveats.", "input": "Matrix: oil matrix (hexane); Analytes: caffeine analogs; Column: Phenyl-hexyl, 3.0×100 mm, 3 µm; Oven 25°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Gradient 5→80% B over 10 min; Flow 0.40 mL/min. Observation: basic amines tail at pH>6; poor retention at low organic.", "output": "Likely causes and actions:\n1) Try without ion-pair first using acidic pH and endcapped C18; assess tailing.\n2) If needed, test HFBA/TFA (UV penalty) or volatile IP reagents for MS with caution.\n3) Document equilibration burden and memory effects; dedicate system if adopting IP.\n4) Consider polar-embedded or mixed-mode columns as alternatives.\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "ion_pair", "detector": "MS", "instrument": "HPLC"}}
{"instruction": "Decide on ion-pairing conditions and caveats.", "input": "Matrix: milk; Analytes: sugars; Column: C18, 4.6×150 mm, 5 µm; Oven 30°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Gradient 10→60% B over 6 min; Flow 0.30 mL/min. Observation: basic amines tail at pH>6; poor retention at low organic.", "output": "Likely causes and actions:\n1) Try without ion-pair first using acidic pH and endcapped C18; assess tailing.\n2) If needed, test HFBA/TFA (UV penalty) or volatile IP reagents for MS with caution.\n3) Document equilibration burden and memory effects; dedicate system if adopting IP.\n4) Consider polar-embedded or mixed-mode columns as alternatives.\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "ion_pair", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: wastewater influent; Analytes: acidic herbicides (pKa 2–4); Column: C8, 4.6×100 mm, 3.5 µm; Oven 35°C; A: water + 0.05% TFA; B: ACN; Isocratic 50% B; Flow 0.30 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "temperature", "detector": "PDA", "instrument": "UHPLC"}}
{"instruction": "Fix peak tailing/broadening/splitting.", "input": "Matrix: groundwater; Analytes: caffeine analogs; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 40°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Isocratic 40% B; Flow 0.50 mL/min. Observation: tailing factor ~1.8; occasional split peaks on main analyte.", "output": "Likely causes and actions:\n1) Match sample solvent to initial mobile phase; dilute strong solvents.\n2) Lower pH to suppress ionization for bases (pH 2.8–3.2) or raise for acids (pH 6.5–7.5).\n3) Consider polar-embedded/C18-AQ or PFP to reduce secondary interactions.\n4) Replace guard; check for column void (reverse flush briefly).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "peak_shape", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Reduce carryover observed in blanks after high standards.", "input": "Matrix: polymer extract; Analytes: caffeine analogs; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 35°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 40% B; Flow 0.40 mL/min. Observation: blank after high standard shows 0.5–2% residual peak.", "output": "Likely causes and actions:\n1) Strengthen needle wash (≥80% organic + 0.1% acid); extend wash cycles.\n2) Include a high-organic purge step between runs; evaluate backflush if available.\n3) Use low-adsorption vials/caps; check sample loop/syringe cleanliness.\n4) Set acceptance carryover <0.1% of high standard peak area.\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "carryover", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Diagnose bubble/degassing issues causing ripple.", "input": "Matrix: urine; Analytes: azo dyes; Column: C18, 2.1×100 mm, 1.7 µm; Oven 40°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Isocratic 50% B; Flow 1.0 mL/min. Observation: periodic bubble bursts; UV shows spikes.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "degassing", "detector": "MS", "instrument": "HPLC"}}
{"instruction": "Eliminate ghost peaks seen in solvent blanks.", "input": "Matrix: wastewater effluent; Analytes: azo dyes; Column: PFP, 2.1×100 mm, 1.9 µm; Oven 45°C; A: water + 0.1% FA; B: ACN; Isocratic 60% B; Flow 0.50 mL/min. Observation: ghost peaks in solvent blanks at random RTs.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "ghost_peaks", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Reduce carryover observed in blanks after high standards.", "input": "Matrix: pharma API in diluent; Analytes: azo dyes; Column: PFP, 2.1×100 mm, 1.9 µm; Oven 30°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Isocratic 35% B; Flow 0.50 mL/min. Observation: blank after high standard shows 0.5–2% residual peak.", "output": "Likely causes and actions:\n1) Strengthen needle wash (≥80% organic + 0.1% acid); extend wash cycles.\n2) Include a high-organic purge step between runs; evaluate backflush if available.\n3) Use low-adsorption vials/caps; check sample loop/syringe cleanliness.\n4) Set acceptance carryover <0.1% of high standard peak area.\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "carryover", "detector": "FLD", "instrument": "UHPLC"}}
{"instruction": "Reduce carryover observed in blanks after high standards.", "input": "Matrix: polymer extract; Analytes: polyphenols; Column: PFP, 2.1×100 mm, 1.9 µm; Oven 35°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Gradient 5→40% B over 20 min; Flow 0.40 mL/min. Observation: blank after high standard shows 0.5–2% residual peak.", "output": "Likely causes and actions:\n1) Strengthen needle wash (≥80% organic + 0.1% acid); extend wash cycles.\n2) Include a high-organic purge step between runs; evaluate backflush if available.\n3) Use low-adsorption vials/caps; check sample loop/syringe cleanliness.\n4) Set acceptance carryover <0.1% of high standard peak area.\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "carryover", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Propose starting conditions for HPLC method development.", "input": "Matrix: wastewater influent; Analytes: steroids; Column: PFP, 2.1×100 mm, 1.9 µm; Oven 25°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Gradient 5→95% B over 12 min; Flow 0.50 mL/min. Goal: fast baseline method to separate target class within 8–12 min.", "output": "Likely causes and actions:\n1) Start: C18 or PFP; 35–40°C; 1.0 mL/min (4.6 mm) or 0.3–0.5 mL/min (2.1 mm).\n2) Acidic mobile for bases: A 10 mM ammonium formate + 0.1% FA; B ACN.\n3) Gradient 5→40% B in 10–12 min; adjust to hit k′ 2–10 and Rs>1.5 for critical pairs.\n4) If poor retention at low %B, try C18-AQ or phenyl-hexyl; consider HILIC for very polar.\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "method_dev", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Fix peak tailing/broadening/splitting.", "input": "Matrix: tablet dissolution (pH 6.8); Analytes: caffeine analogs; Column: C18, 4.6×150 mm, 5 µm; Oven 45°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Gradient 2→60% B over 15 min; Flow 0.30 mL/min. Observation: tailing factor ~1.8; occasional split peaks on main analyte.", "output": "Likely causes and actions:\n1) Match sample solvent to initial mobile phase; dilute strong solvents.\n2) Lower pH to suppress ionization for bases (pH 2.8–3.2) or raise for acids (pH 6.5–7.5).\n3) Consider polar-embedded/C18-AQ or PFP to reduce secondary interactions.\n4) Replace guard; check for column void (reverse flush briefly).\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "peak_shape", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: cosmetics extract (IPA); Analytes: glycosides; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 35°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Gradient 5→40% B over 15 min; Flow 1.0 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "temperature", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Reduce carryover observed in blanks after high standards.", "input": "Matrix: urine; Analytes: beta-lactams; Column: C18, 4.6×150 mm, 5 µm; Oven 25°C; A: water + 0.05% TFA; B: ACN; Isocratic 60% B; Flow 0.40 mL/min. Observation: blank after high standard shows 0.5–2% residual peak.", "output": "Likely causes and actions:\n1) Strengthen needle wash (≥80% organic + 0.1% acid); extend wash cycles.\n2) Include a high-organic purge step between runs; evaluate backflush if available.\n3) Use low-adsorption vials/caps; check sample loop/syringe cleanliness.\n4) Set acceptance carryover <0.1% of high standard peak area.\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "carryover", "detector": "MS", "instrument": "HPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: plasma; Analytes: acidic herbicides (pKa 2–4); Column: PFP, 2.1×100 mm, 1.9 µm; Oven 30°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Gradient 10→60% B over 12 min; Flow 0.50 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "temperature", "detector": "FLD", "instrument": "UHPLC"}}
{"instruction": "Reduce carryover observed in blanks after high standards.", "input": "Matrix: urine; Analytes: beta-lactams; Column: Phenyl-hexyl, 3.0×100 mm, 3 µm; Oven 35°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 40% B; Flow 0.50 mL/min. Observation: blank after high standard shows 0.5–2% residual peak.", "output": "Likely causes and actions:\n1) Strengthen needle wash (≥80% organic + 0.1% acid); extend wash cycles.\n2) Include a high-organic purge step between runs; evaluate backflush if available.\n3) Use low-adsorption vials/caps; check sample loop/syringe cleanliness.\n4) Set acceptance carryover <0.1% of high standard peak area.\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "carryover", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Decide on ion-pairing conditions and caveats.", "input": "Matrix: cosmetics extract (IPA); Analytes: neutral pesticides; Column: Polar-embedded C18, 2.1×150 mm, 3 µm; Oven 35°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Gradient 2→40% B over 8 min; Flow 0.50 mL/min. Observation: basic amines tail at pH>6; poor retention at low organic.", "output": "Likely causes and actions:\n1) Try without ion-pair first using acidic pH and endcapped C18; assess tailing.\n2) If needed, test HFBA/TFA (UV penalty) or volatile IP reagents for MS with caution.\n3) Document equilibration burden and memory effects; dedicate system if adopting IP.\n4) Consider polar-embedded or mixed-mode columns as alternatives.\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "ion_pair", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Diagnose bubble/degassing issues causing ripple.", "input": "Matrix: urine; Analytes: vitamins (B-group); Column: C18, 2.1×100 mm, 1.7 µm; Oven 40°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Gradient 2→95% B over 20 min; Flow 0.50 mL/min. Observation: periodic bubble bursts; UV shows spikes.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "degassing", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Diagnose retention time drift >5%.", "input": "Matrix: food homogenate; Analytes: beta-lactams; Column: C8, 4.6×100 mm, 3.5 µm; Oven 40°C; A: water + 0.1% FA; B: ACN; Isocratic 30% B; Flow 1.0 mL/min. Observation: RT drifts +6–10% over a batch of 30 samples.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "RT_drift", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Fix autosampler needle seat leak/cross-contamination.", "input": "Matrix: urine; Analytes: vitamins (B-group); Column: C8, 4.6×100 mm, 3.5 µm; Oven 25°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 60% B; Flow 1.0 mL/min. Observation: variable injection volumes; leaks near needle seat.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "autosampler", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Resolve buffer pH/precipitation/mixing problems.", "input": "Matrix: pharma API in diluent; Analytes: PFAS (PFOS/PFOA); Column: C18, 2.1×100 mm, 1.7 µm; Oven 40°C; A: water + 0.1% FA; B: ACN; Gradient 2→40% B over 20 min; Flow 1.0 mL/min. Observation: salt precipitation suspected at high % organic.", "output": "Likely causes and actions:\n1) Use volatile buffers (ammonium formate/acetate) at ≤10–20 mM for MS; check pH at run temp.\n2) Avoid high-salt transitions to 100% organic; flush with salt-free aqueous before.\n3) Filter and degas buffers; replace after 48 h; verify miscibility A/B.\n4) At low pH for bases, add 0.1% FA; for strong tailing, consider 2–5 mM TFA (UV penalty).\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "buffer", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Stabilize noisy or drifting baseline.", "input": "Matrix: milk; Analytes: azo dyes; Column: C18, 2.1×100 mm, 1.7 µm; Oven 25°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 40% B; Flow 1.0 mL/min. Observation: baseline ripple and drift during gradient; S/N reduced.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "baseline", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Ensure sufficient column equilibration between runs.", "input": "Matrix: tablet dissolution (pH 6.8); Analytes: sugars; Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 45°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Isocratic 40% B; Flow 0.40 mL/min. Observation: first run after gradient shift differs from subsequent runs.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "equilibration", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Resolve buffer pH/precipitation/mixing problems.", "input": "Matrix: milk; Analytes: glycosides; Column: PFP, 2.1×100 mm, 1.9 µm; Oven 40°C; A: water + 0.05% TFA; B: ACN; Gradient 5→95% B over 12 min; Flow 0.50 mL/min. Observation: salt precipitation suspected at high % organic.", "output": "Likely causes and actions:\n1) Use volatile buffers (ammonium formate/acetate) at ≤10–20 mM for MS; check pH at run temp.\n2) Avoid high-salt transitions to 100% organic; flush with salt-free aqueous before.\n3) Filter and degas buffers; replace after 48 h; verify miscibility A/B.\n4) At low pH for bases, add 0.1% FA; for strong tailing, consider 2–5 mM TFA (UV penalty).\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "buffer", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Resolve pump pulsation/check valve problems.", "input": "Matrix: polymer extract; Analytes: neutral pesticides; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 40°C; A: water + 0.1% FA; B: ACN; Gradient 5→60% B over 12 min; Flow 1.0 mL/min. Observation: pulsation visible on pressure trace; peak area RSD ~6%.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "pump", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Eliminate ghost peaks seen in solvent blanks.", "input": "Matrix: beer; Analytes: vitamins (B-group); Column: C18, 4.6×150 mm, 5 µm; Oven 25°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Isocratic 50% B; Flow 0.40 mL/min. Observation: ghost peaks in solvent blanks at random RTs.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "ghost_peaks", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Resolve buffer pH/precipitation/mixing problems.", "input": "Matrix: leaf extract; Analytes: alkylbenzene sulfonates; Column: C18, 4.6×150 mm, 5 µm; Oven 40°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Gradient 10→40% B over 8 min; Flow 0.30 mL/min. Observation: salt precipitation suspected at high % organic.", "output": "Likely causes and actions:\n1) Use volatile buffers (ammonium formate/acetate) at ≤10–20 mM for MS; check pH at run temp.\n2) Avoid high-salt transitions to 100% organic; flush with salt-free aqueous before.\n3) Filter and degas buffers; replace after 48 h; verify miscibility A/B.\n4) At low pH for bases, add 0.1% FA; for strong tailing, consider 2–5 mM TFA (UV penalty).\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "buffer", "detector": "FLD", "instrument": "UHPLC"}}
{"instruction": "Eliminate ghost peaks seen in solvent blanks.", "input": "Matrix: food homogenate; Analytes: beta-lactams; Column: C18, 4.6×150 mm, 5 µm; Oven 35°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Isocratic 40% B; Flow 0.30 mL/min. Observation: ghost peaks in solvent blanks at random RTs.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "ghost_peaks", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Fix peak tailing/broadening/splitting.", "input": "Matrix: groundwater; Analytes: beta-lactams; Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 25°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Gradient 10→60% B over 12 min; Flow 1.0 mL/min. Observation: tailing factor ~1.8; occasional split peaks on main analyte.", "output": "Likely causes and actions:\n1) Match sample solvent to initial mobile phase; dilute strong solvents.\n2) Lower pH to suppress ionization for bases (pH 2.8–3.2) or raise for acids (pH 6.5–7.5).\n3) Consider polar-embedded/C18-AQ or PFP to reduce secondary interactions.\n4) Replace guard; check for column void (reverse flush briefly).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "peak_shape", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: urine; Analytes: glycosides; Column: Polar-embedded C18, 2.1×150 mm, 3 µm; Oven 45°C; A: water + 0.1% FA; B: ACN; Isocratic 60% B; Flow 0.40 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "temperature", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Resolve buffer pH/precipitation/mixing problems.", "input": "Matrix: urine; Analytes: sugars; Column: Polar-embedded C18, 2.1×150 mm, 3 µm; Oven 40°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 40% B; Flow 0.30 mL/min. Observation: salt precipitation suspected at high % organic.", "output": "Likely causes and actions:\n1) Use volatile buffers (ammonium formate/acetate) at ≤10–20 mM for MS; check pH at run temp.\n2) Avoid high-salt transitions to 100% organic; flush with salt-free aqueous before.\n3) Filter and degas buffers; replace after 48 h; verify miscibility A/B.\n4) At low pH for bases, add 0.1% FA; for strong tailing, consider 2–5 mM TFA (UV penalty).\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "buffer", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: drinking water; Analytes: neutral pesticides; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 40°C; A: water + 0.05% TFA; B: ACN; Isocratic 35% B; Flow 0.50 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "temperature", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Resolve buffer pH/precipitation/mixing problems.", "input": "Matrix: groundwater; Analytes: glycosides; Column: C18, 4.6×150 mm, 5 µm; Oven 45°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Isocratic 40% B; Flow 0.50 mL/min. Observation: salt precipitation suspected at high % organic.", "output": "Likely causes and actions:\n1) Use volatile buffers (ammonium formate/acetate) at ≤10–20 mM for MS; check pH at run temp.\n2) Avoid high-salt transitions to 100% organic; flush with salt-free aqueous before.\n3) Filter and degas buffers; replace after 48 h; verify miscibility A/B.\n4) At low pH for bases, add 0.1% FA; for strong tailing, consider 2–5 mM TFA (UV penalty).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "buffer", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Diagnose bubble/degassing issues causing ripple.", "input": "Matrix: soil extract (MeOH); Analytes: vitamins (B-group); Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 35°C; A: water + 0.05% TFA; B: ACN; Gradient 5→95% B over 10 min; Flow 0.40 mL/min. Observation: periodic bubble bursts; UV shows spikes.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "degassing", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Fix autosampler needle seat leak/cross-contamination.", "input": "Matrix: groundwater; Analytes: acidic herbicides (pKa 2–4); Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 40°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 40% B; Flow 0.30 mL/min. Observation: variable injection volumes; leaks near needle seat.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "autosampler", "detector": "PDA", "instrument": "UHPLC"}}
{"instruction": "Diagnose column frit clogging or void formation.", "input": "Matrix: wine; Analytes: basic amines (pKa 8–10); Column: C18, 4.6×150 mm, 5 µm; Oven 45°C; A: water + 0.05% TFA; B: ACN; Isocratic 30% B; Flow 0.50 mL/min. Observation: plate count dropped 40%; asymmetry 1.7; possible void.", "output": "Likely causes and actions:\n1) Check asymmetry and plates with a system suitability compound.\n2) Reverse-flush 5–10 min; replace guard; inspect for voids (shoulder/doublet).\n3) Reduce max pressure; verify fittings/ferrules to prevent channeling.\n4) Log column volumes; retire if performance out of spec.\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "column_health", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Stabilize noisy or drifting baseline.", "input": "Matrix: milk; Analytes: neutral pesticides; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 35°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Gradient 2→40% B over 8 min; Flow 1.0 mL/min. Observation: baseline ripple and drift during gradient; S/N reduced.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "baseline", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Diagnose bubble/degassing issues causing ripple.", "input": "Matrix: wine; Analytes: steroids; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 40°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Gradient 5→40% B over 20 min; Flow 1.0 mL/min. Observation: periodic bubble bursts; UV shows spikes.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "degassing", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Address temperature-related retention and viscosity issues.", "input": "Matrix: plasma; Analytes: amino acids; Column: C8, 4.6×100 mm, 3.5 µm; Oven 40°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Gradient 2→40% B over 12 min; Flow 0.50 mL/min. Observation: RT shortens 3–5% when lab ambient increases; viscosity changes.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "temperature", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Eliminate ghost peaks seen in solvent blanks.", "input": "Matrix: oil matrix (hexane); Analytes: azo dyes; Column: C18, 2.1×100 mm, 1.7 µm; Oven 45°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Gradient 2→60% B over 15 min; Flow 0.40 mL/min. Observation: ghost peaks in solvent blanks at random RTs.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "ghost_peaks", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Decide on ion-pairing conditions and caveats.", "input": "Matrix: oil matrix (hexane); Analytes: PFAS (PFOS/PFOA); Column: C18, 2.1×100 mm, 1.7 µm; Oven 35°C; A: water + 0.05% TFA; B: ACN; Isocratic 30% B; Flow 0.40 mL/min. Observation: basic amines tail at pH>6; poor retention at low organic.", "output": "Likely causes and actions:\n1) Try without ion-pair first using acidic pH and endcapped C18; assess tailing.\n2) If needed, test HFBA/TFA (UV penalty) or volatile IP reagents for MS with caution.\n3) Document equilibration burden and memory effects; dedicate system if adopting IP.\n4) Consider polar-embedded or mixed-mode columns as alternatives.\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "ion_pair", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Diagnose bubble/degassing issues causing ripple.", "input": "Matrix: polymer extract; Analytes: phenols; Column: C8, 4.6×100 mm, 3.5 µm; Oven 30°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Isocratic 30% B; Flow 1.0 mL/min. Observation: periodic bubble bursts; UV shows spikes.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "degassing", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Stabilize noisy or drifting baseline.", "input": "Matrix: QC standard in water; Analytes: neutral pesticides; Column: C18, 4.6×150 mm, 5 µm; Oven 45°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Isocratic 50% B; Flow 0.50 mL/min. Observation: baseline ripple and drift during gradient; S/N reduced.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "baseline", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Stabilize noisy or drifting baseline.", "input": "Matrix: river water; Analytes: acidic herbicides (pKa 2–4); Column: Polar-embedded C18, 2.1×150 mm, 3 µm; Oven 45°C; A: water + 0.1% FA; B: ACN; Isocratic 60% B; Flow 0.40 mL/min. Observation: baseline ripple and drift during gradient; S/N reduced.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "baseline", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Ensure sufficient column equilibration between runs.", "input": "Matrix: QC standard in water; Analytes: steroids; Column: PFP, 2.1×100 mm, 1.9 µm; Oven 25°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 50% B; Flow 0.40 mL/min. Observation: first run after gradient shift differs from subsequent runs.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "equilibration", "detector": "PDA", "instrument": "UHPLC"}}
{"instruction": "Diagnose retention time drift >5%.", "input": "Matrix: leaf extract; Analytes: bile acids; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 35°C; A: water + 0.1% FA; B: ACN; Gradient 2→95% B over 6 min; Flow 0.50 mL/min. Observation: RT drifts +6–10% over a batch of 30 samples.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "RT_drift", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Fix autosampler needle seat leak/cross-contamination.", "input": "Matrix: river water; Analytes: alkylbenzene sulfonates; Column: C8, 4.6×100 mm, 3.5 µm; Oven 25°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Isocratic 30% B; Flow 1.0 mL/min. Observation: variable injection volumes; leaks near needle seat.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: carryover <0.1% of high standard; blank shows no analyte peaks.", "meta": {"topic": "autosampler", "detector": "MS", "instrument": "HPLC"}}
{"instruction": "Decide on ion-pairing conditions and caveats.", "input": "Matrix: wine; Analytes: caffeine analogs; Column: C18, 4.6×150 mm, 5 µm; Oven 25°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Gradient 10→80% B over 6 min; Flow 0.50 mL/min. Observation: basic amines tail at pH>6; poor retention at low organic.", "output": "Likely causes and actions:\n1) Try without ion-pair first using acidic pH and endcapped C18; assess tailing.\n2) If needed, test HFBA/TFA (UV penalty) or volatile IP reagents for MS with caution.\n3) Document equilibration burden and memory effects; dedicate system if adopting IP.\n4) Consider polar-embedded or mixed-mode columns as alternatives.\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "ion_pair", "detector": "MS", "instrument": "HPLC"}}
{"instruction": "Diagnose retention time drift >5%.", "input": "Matrix: cosmetics extract (IPA); Analytes: beta-lactams; Column: C18, 2.1×100 mm, 1.7 µm; Oven 35°C; A: water + 0.1% FA; B: ACN; Isocratic 35% B; Flow 0.50 mL/min. Observation: RT drifts +6–10% over a batch of 30 samples.", "output": "Likely causes and actions:\n1) Verify oven setpoint holds within ±0.1°C; allow ≥15 min stabilization.\n2) Increase post-gradient equilibration to ≥10–15 column volumes.\n3) Prime A/B 5 min to remove composition drift; verify mixer volume.\n4) Run bracketing standards every 10 injections; apply RT window ±2%.\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "RT_drift", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Diagnose column frit clogging or void formation.", "input": "Matrix: drinking water; Analytes: bile acids; Column: C18, 4.6×150 mm, 5 µm; Oven 35°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Gradient 5→80% B over 20 min; Flow 0.40 mL/min. Observation: plate count dropped 40%; asymmetry 1.7; possible void.", "output": "Likely causes and actions:\n1) Check asymmetry and plates with a system suitability compound.\n2) Reverse-flush 5–10 min; replace guard; inspect for voids (shoulder/doublet).\n3) Reduce max pressure; verify fittings/ferrules to prevent channeling.\n4) Log column volumes; retire if performance out of spec.\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "column_health", "detector": "MS", "instrument": "UHPLC"}}
{"instruction": "Decide on ion-pairing conditions and caveats.", "input": "Matrix: groundwater; Analytes: phenols; Column: Phenyl-hexyl, 3.0×100 mm, 3 µm; Oven 40°C; A: 10 mM ammonium bicarbonate (pH 9.0); B: ACN; Gradient 10→95% B over 12 min; Flow 1.0 mL/min. Observation: basic amines tail at pH>6; poor retention at low organic.", "output": "Likely causes and actions:\n1) Try without ion-pair first using acidic pH and endcapped C18; assess tailing.\n2) If needed, test HFBA/TFA (UV penalty) or volatile IP reagents for MS with caution.\n3) Document equilibration burden and memory effects; dedicate system if adopting IP.\n4) Consider polar-embedded or mixed-mode columns as alternatives.\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "ion_pair", "detector": "UV", "instrument": "HPLC"}}
{"instruction": "Fix autosampler needle seat leak/cross-contamination.", "input": "Matrix: river water; Analytes: polyphenols; Column: C8, 4.6×100 mm, 3.5 µm; Oven 45°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Isocratic 35% B; Flow 1.0 mL/min. Observation: variable injection volumes; leaks near needle seat.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "autosampler", "detector": "PDA", "instrument": "HPLC"}}
{"instruction": "Troubleshoot high backpressure increase vs baseline.", "input": "Matrix: drinking water; Analytes: PFAS (PFOS/PFOA); Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 35°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 50% B; Flow 0.50 mL/min. Observation: pressure increased 30–50% vs yesterday; pulses under gradient.", "output": "Likely causes and actions:\n1) Bypass column to assess system backpressure; replace inline filter and frits (0.2 µm).\n2) Flush column: 50:50 water:organic (10 min) → 100% organic (10 min) → 100% water (10 min).\n3) Check solvent miscibility; remove salts before 100% organic to avoid precipitation.\n4) Inspect pump seals/check valves; verify degasser performance (vacuum level OK).\nAcceptance: backpressure within ±10% of baseline; plate count within spec.", "meta": {"topic": "pressure", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Fix autosampler needle seat leak/cross-contamination.", "input": "Matrix: leaf extract; Analytes: sugars; Column: C18-AQ, 2.1×150 mm, 3 µm; Oven 25°C; A: 20 mM ammonium acetate (pH 6.8); B: ACN; Isocratic 40% B; Flow 1.0 mL/min. Observation: variable injection volumes; leaks near needle seat.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "autosampler", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Fix peak tailing/broadening/splitting.", "input": "Matrix: food homogenate; Analytes: basic amines (pKa 8–10); Column: PFP, 2.1×100 mm, 1.9 µm; Oven 30°C; A: water + 0.1% FA; B: ACN; Gradient 10→80% B over 6 min; Flow 1.0 mL/min. Observation: tailing factor ~1.8; occasional split peaks on main analyte.", "output": "Likely causes and actions:\n1) Match sample solvent to initial mobile phase; dilute strong solvents.\n2) Lower pH to suppress ionization for bases (pH 2.8–3.2) or raise for acids (pH 6.5–7.5).\n3) Consider polar-embedded/C18-AQ or PFP to reduce secondary interactions.\n4) Replace guard; check for column void (reverse flush briefly).\nAcceptance: S/N > 10 at LOQ; baseline drift <5% over run.", "meta": {"topic": "peak_shape", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Resolve pump pulsation/check valve problems.", "input": "Matrix: polymer extract; Analytes: polyphenols; Column: HILIC amide, 2.1×100 mm, 1.7 µm; Oven 35°C; A: 50 mM ammonium formate (pH 3.2); B: MeOH; Gradient 5→60% B over 6 min; Flow 0.40 mL/min. Observation: pulsation visible on pressure trace; peak area RSD ~6%.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "pump", "detector": "UV", "instrument": "UHPLC"}}
{"instruction": "Troubleshoot high backpressure increase vs baseline.", "input": "Matrix: serum; Analytes: azo dyes; Column: C8, 4.6×100 mm, 3.5 µm; Oven 30°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Gradient 2→60% B over 15 min; Flow 0.50 mL/min. Observation: pressure increased 30–50% vs yesterday; pulses under gradient.", "output": "Likely causes and actions:\n1) Bypass column to assess system backpressure; replace inline filter and frits (0.2 µm).\n2) Flush column: 50:50 water:organic (10 min) → 100% organic (10 min) → 100% water (10 min).\n3) Check solvent miscibility; remove salts before 100% organic to avoid precipitation.\n4) Inspect pump seals/check valves; verify degasser performance (vacuum level OK).\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "pressure", "detector": "FLD", "instrument": "HPLC"}}
{"instruction": "Fix autosampler needle seat leak/cross-contamination.", "input": "Matrix: tablet dissolution (pH 6.8); Analytes: alkylbenzene sulfonates; Column: Polar-embedded C18, 2.1×150 mm, 3 µm; Oven 40°C; A: 5 mM ammonium acetate in water (pH ~5.0); B: MeOH; Isocratic 40% B; Flow 0.30 mL/min. Observation: variable injection volumes; leaks near needle seat.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: Rs>1.5 for critical pair, asymmetry 0.9–1.3, %RSD RT <1.0%.", "meta": {"topic": "autosampler", "detector": "PDA", "instrument": "UHPLC"}}
{"instruction": "Diagnose bubble/degassing issues causing ripple.", "input": "Matrix: wine; Analytes: glycosides; Column: C18, 4.6×150 mm, 5 µm; Oven 25°C; A: 10 mM ammonium formate + 0.1% FA in water (pH ~3.2); B: ACN; Isocratic 30% B; Flow 0.50 mL/min. Observation: periodic bubble bursts; UV shows spikes.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: k′ between 2–10; tailing factor <1.3; RT window ±2%.", "meta": {"topic": "degassing", "detector": "FLD", "instrument": "UHPLC"}}
{"instruction": "Resolve pump pulsation/check valve problems.", "input": "Matrix: cosmetics extract (IPA); Analytes: alkylbenzene sulfonates; Column: C18, 2.1×100 mm, 1.7 µm; Oven 40°C; A: water + 0.05% TFA; B: ACN; Gradient 2→95% B over 6 min; Flow 0.40 mL/min. Observation: pulsation visible on pressure trace; peak area RSD ~6%.", "output": "Likely causes and actions:\n1) Run solvent and system blanks; isolate source by bypassing modules.\n2) Replace suspect solvents; ensure fresh buffer (≤48 h) and proper filtration (0.2 µm).\n3) Inspect degasser (vacuum level, tubing kinks) and pump check valves/seals.\n4) Perform needle-seat test, adjust wash, and verify no leaks (draw-air test).\nAcceptance: recovery 80–120%, precision (%RSD) ≤5% for n=6.", "meta": {"topic": "pump", "detector": "PDA", "instrument": "HPLC"}}