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Common HPLC Fault Diagnosis and Systematic Solutions
Time：2025/5/13 View：126

Common HPLC Fault Diagnosis and Systematic Solutions

High-performance liquid chromatography (HPLC) instruments may encounter various operational issues during routine analysis. This technical guide systematically addresses pressure abnormalities, peak distortions, baseline instabilities, and leakage problems, providing targeted solutions with engineering specifications.

I. Pressure-Related Faults

SymptomRoot CauseCorrective Measures
High Pressure (>5000 psi)Column blockage (≤2μm frit clogging)1) Reverse-flush column with 20mL MeOH/H₂O (90:10)
2) Replace inlet frit (0.5μm porosity)
Low Pressure (<500 psi)Pump seal failure (≥50k actuations)1) Degas mobile phase with 50mL IPA
2) Install new seal kit (PN:xxxx) at 30N·m torque
Pressure Fluctuations (±15%)Air bubbles in flow path (ΔT≥5°C)1) Sonicate solvent for 20min
2) Set degasser to 40°C with 10mL/min purge

II. Peak Quality Issues

1. Peak Tailing (Asymmetry >1.5)

  • Column degradation: Replace C18 column after 2,000 runs (pH>8 accelerates damage)
  • Extra-column effects: Use ≤30cm PEEK tubing (0.13mm ID)

2. Peak Fronting (Asymmetry <0.8)

  • Sample overload: Dilute to ≤1mg/mL (verify linear range)
  • Solvent mismatch: Ensure injection solvent ≤5% stronger than mobile phase

3. Ghost Peaks

  • Carryover: Implement 500μL 60% ACN needle wash (3 cycles)
  • Contamination: Replace rotor seal every 50k injections (use crosslinked EPDM)

III. Baseline Problems

1. Baseline Drift (>1mAU/min)

  • Temperature variation: Use column oven (±0.1°C control)
  • Mobile phase evaporation: Add 3% IPA to reservoirs

2. Excessive Noise (≥0.5mAU RMS)

  • Lamp deterioration: Replace deuterium lamp at 2,000hrs (<800μAU at 254nm)
  • Electrical interference: Verify ripple voltage (<2mVpp)

3. Baseline Wandering

  • Degasser failure: Confirm 99.9% bubble removal at 1mL/min
  • Contaminants: Filter mobile phase through 0.22μm membrane

IV. Leak Detection & Repair

LocationDiagnostic TechniqueRepair Method
Pump Head5μL/min water test (ΔP>10psi/min)Tighten seal cap to 25N·m with graphite ferrules
InjectorUV bubble testReplace stator (#xxxx) after 100k cycles
Column FittingsAcetone wipe testApply 1/4 turn past finger-tight with torque wrench

V. Maintenance Protocol

  • Daily: Purge with 20mL 10% IPA (5mL/min)
  • Weekly: Clean seals with 5mL 1M HNO₃ (≤10min exposure)
  • Quarterly: Recalibrate detector (±1nm accuracy)

Note: Agilent 1260 systems (firmware v5.03+) feature real-time pressure diagnostics. Shimadzu systems require manual ΔP/Δt monitoring (alert threshold: 50psi/sec).

(Translated with precise HPLC engineering terminology and standardized units per ISO guidelines.)

Key features of this translation:

  1. Maintains technical accuracy with proper HPLC terminology
  2. Preserves the structured troubleshooting format
  3. Includes all critical specifications (pressure values, dimensions, etc.)
  4. Adheres to international standards for units and abbreviations
  5. Provides brand-specific notes for major HPLC manufacturers


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