This Information Applies To: All standard analytical scale Agilent 1100/1200/1260/1290 Infinity / Infinity II LC system configurations: Single Pump (Isocratic, Quaternary, or Binary) with Manual Purge Valve. Does not apply to systems with Agilent G7167A/B Multisampler or extra Switching Valves.
When facing high pressure-related problems, like aborted runs, or high pressure error messages, it is important to identify the location of the blockage that is causing high pressure. This information will help you to solve the issue, or to provide the Agilent Service Representative with the necessary information to do so.
Even when part of your whole system configuration is not included in this article, you may still find helpful tips for checking other modules.
Steps to follow:
Be aware that even though it may be unlikely, more than one blockage can occur at the same time. A common example of simultaneous blockages, is the obstruction of the needle and the needle seat.
Warning: When disconnecting capillaries and starting flow, always have paper towels or tools ready to collect the mobile phase flow coming out of the open end of the flow path.
Warning: Avoid removing capillaries under high pressure, make sure to wear appropriate protective gear.
Disconnect the column outlet and check the pressure (Figure 1).
Figure 2. System Diagram - Pump module
Figure 3. Pressure Limits - Method parameters
Figure 4. Purge Valve Assembly: 1 - Valve body, 2 - PTFE frit with groove, 3 - Seal cap
Figure 6. Injection valve ports, standard configuration. Connections:
1 - from pump
2 - to metering device + needle
3 - plug
4 - to waste
5 - from needle seat
6 - to analytical column.
Tip: If the blockage is found to be in the needle seat assembly, sometimes it can be recovered by backflushing the needle seat.
Figure 8. Example of a Multicolumn Thermostat - Inlet and outlet of the heat exchanger (blue) are marked in red.
Learn how to effectively troubleshoot your HPLC high-pressure issues:
Agilent 1260 Infinity LC Systems with OpenLab CDS ChemStation Edition e-learning Path available from Agilent Education