youhana Hosny 1 year ago

Column temperature fluctuation – Use a thermostat column oven. Use a thermometer to check the accuracy of the set temperature.
Incorrect mobile phase composition – Prepare fresh mobile phase. Check mixer is working for gradient methods.
Contamination of detector flow cell – Flush flow cell with a strong organic solvent. If no improvement is seen, change the flow cell.
Damaged flow cell – Replace flow cell.
Pump outlet blocked – Remove blockage. If no improvement is seen, replace outlet.
Flow rate change – Reset flow rate. Test using liquid flow meter.
Poor column equilibration – Increase column equilibration time. If recently changed mobile phase, purge the system and pump of old solvent with new mobile phase using 20 column volumes.
Retained peaks look like baseline drifts –Use a guard column. Thoroughly flush the column with a strong organic solvent before the next injection.
UV detector not set at maximum absorbance – Use maximum absorbance wavelength of target compound(s)
Reference wavelength of detector is incorrect – Ensure reference wavelength of the detector is different to target compounds.
UV absorbing mobile phase – Use non-UV absorbing HPLC grade solvent.