I run HPLC 1260, during analysis, we have seen that there was deposition of dried salts in the knot of outlet valve, injecting site , and in thermo too. We are using Millipore water for hplc mobile phase preparation and column washing. Can anyone have idea how much conductivity of water is limited in Millipore water and how can we take care of those salts in hplc? And What may be the reason behind that salt deposition and how to control that?

  • If salt residues are seen all over the LC, they usually originate from buffers. Although there's no problem in using buffers, they should only be on the system when needed. Once the sequence is over, the system should be thoroughly flushed with fresh water. The system should not be left in buffer or water, so going for a final flush with good quality IPA (after flushing with water) is the proper way.

    I suspect that there might be some leaks on the system, so running a leak test from LabAdvisor seems to be a good idea. Make sure the system gets a PM on an annual basis.

    One more thing: When using buffers, there is usually no need to go to 100% organic. Above 70-80% organic, you'll see precipitation of crystals, which can block your system or damage parts. You can try this in a test tube experiment.

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