Q: Why is the HPLC baseline noisy?
A: Common reasons include air bubbles in the system, an aging detector lamp, a contaminated flow cell, or impurities in the mobile phase.
#BaselineTroubleshooting
Q: What causes a drifting baseline?
A: Likely factors are temperature variations, changes in mobile phase composition, or instability in the detector lamp.
Q: Why do ghost peaks appear during blank runs?
A: Possible sources include mobile phase contamination, carryover from earlier injections, or memory effects from the column.
Q: Why are my peaks splitting?
A: Causes may include overloading the column, mismatch between sample solvent and mobile phase, or unintended double injection.
#PeakSplitting #ColumnOverload
Q: What leads to fronting (leading peaks)?
A: Often due to column overload, poor packing quality, or injecting too large a sample volume.
Q: Why do I observe peak tailing?
A: This can result from strong interactions between analytes and the stationary phase or from column degradation.
#PeakTailing #ColumnTroubleshooting
Q: Why is retention time shifting?
A: Typically caused by inconsistent mobile phase composition, temperature changes, or an aging column.
#RetentionShift
Q: What results in low detector sensitivity?
A: A dirty detector cell, an old lamp, poor sample preparation, or low analyte concentration.
#HPLCDetection
Q: What causes high system pressure?
A: Blocked frits, a contaminated column, or clogged tubing are common culprits.
Q: Why is the system pressure low?
A: Could be due to leaks, worn pump seals, or an empty solvent reservoir.
Q: Why is there no flow from the pump?
A: Causes include air locks, a dry pump, or mechanical pump failure.
#HLPCPump
Q: Why is the pump making noise?
A: May be caused by air trapped in the system, worn piston seals, or malfunctioning check valves.
#PumpNoise
Q: Why is the detector unresponsive?
A: Check for a powered-off lamp, disconnected signal cables, or a defective detector.
#DetectorFail #NoSignal
Q: What causes air bubbles in the detector cell?
A: Insufficient degassing, loose connections, or small system leaks.
#AirBubbles
Q: Why is the peak area inconsistent?
A: Potential causes include autosampler errors, a faulty syringe, or inconsistent injection volumes.
#PeakArea
Q: What causes sudden changes in peak shape?
A: Likely due to column contamination or an unexpected change in the mobile phase.
Q: Why has column backpressure suddenly increased?
A: May be caused by precipitation from the sample matrix or mobile phase blocking the column.
Q: What leads to broad peaks?
A: Reasons include overloading the column, using an old or worn column, or operating at a slow flow rate.
Q: Why is there carryover in blank runs?
A: Inadequate needle wash, sticky analytes, or a contaminated injection needle may be responsible.
#Carryover
Q: What causes variability in retention times?
A: Often due to inconsistent flow rates or variations in mobile phase composition.
Q: Why isn’t the gradient working as expected?
A: Possible causes include gradient valve malfunctions, incorrect software settings, or air bubbles in the solvent lines.
Q: What causes leakage near the detector?
A: Most likely due to loose fittings or a cracked detector flow cell.
Q: Why are sample peaks missing?
A: Could be due to sample degradation, incorrect detector wavelength, or failed injection.
Q: What causes baseline oscillations?
A: Usually due to pump pulsations or trapped air within the system.
Q: Why do I see extra peaks in the chromatogram?
A: Potential causes include sample or system contamination, or ghost peaks from previous runs.