Chromatography Forum

During a recent OQ process, a number of UPLCs were found to be contaminated. We use multiple instruments and this was only happening in certain labs, so we investigated WPS and found that only the lab in question was using Biopak Filters.

Unlike the Millipak, I can't see any specification for particle size for the Biopak, so I was wondering if I could use this filtered water for UPLC.

Does anyone have any experience with these cases, or do you know of any particle size specifications for Biopak?

No. That filter is not for use in HPLC. What type of water are you using for HPLC ? The Biopak filter is not an "HPLC filter". Per the manufacturer's own website, it describes the filter as a POST-STAGE polishing filter for use with MilliQ water designed for cell culture use. It is used AFTER you fill it with MilliQ water (which has already been filtered); ("Biopak ® Polisher is an ultrafiltration cartridge designed to produce water suitable for molecular biology, biochemistry and cell culture"). Cell culture water and HPLC grade water have very different requirements. Please refer to this article for more information:

"What type of Water Should I use for HPLC, UHPLC or LC/MS Analysis?"; https://hplctips.blogspot.com/2013/10/w ... e-for.html

Note: "UPLC" is just a trademark. You are using HPLC (it is always called HPLC, not "UPLC" etc as the pressure used does not change the technique).

Thank you for your response. We'll look into this and take it.

I agree that UPLC is a trademarked name. However, I mentioned it because it seems to be an issue with the inner diameter.

Best regards