Prince:Troubleshooting the Eksigent UPLC system

• If the power bar shows 100% usage, it is highly likely that the nitrogen cylinder is empty.

• If the temperature in the refrigerated region where the sample is stored is not cold, it is highly likely that the condensed water is frozen. The solution is to remove the samples and store it at lower temperature and stop the cooling system by increasing the temperature of the sample storage area until the ice thaws. Note that the best way to access the control window is through a method file rather than the Eksigent control menu.

• If the pressure is very unstable, the tubes might have air bubbles trapped in them. Disconnect the trap and analytical column and purge the system. Always de-gas the solvents and purge the system when adding or changing solvents.

• If the pressure in pump A during the sample loading phase is 0 and the pressure is 0 when the sample runs through analytical column, there is a leak in tube connecting pump A and the trap column.

• If the pressure in pump A during the sample loading phase is normal, however, the pressure is low when the sample runs through analytical column, there is a leak in the tube connecting trap column to the analytical column.

• If the pressure in pump A during the sample loading phase is 0, however, the pressure is normal when sample runs through analytical column, this problem arises due to presence of an air bubble in the sample loading line. This happens usually due to empty sample vials and empty vials which consist of solvent that sandwiches the sample.