Chromatography Forum

Hi all,

I'm not too familiar with the LC/ms/ms we use for pfas analysis, but there was a discussion about contamination seen, precursor/transition ions 263.0 -> 218.9. This has apparently been narrowed down to the methanol used, however it's not every lot of methanol and sometimes not every bottle within the same lot. Anyone familiar with these ions and where they may originate from? Thank you.

Hi all,

Our LC/ms/ms running pfas is seeing high background/contamination when looking at PFPeA; 263.0 -> 218.9. Below is the 500 ppt standard. It is believed to be coming from the methanol used, but it's not every lot, and not even every bottle from a good lot. Any idea? Sorry if this image doesn't display, I'm having trouble with it.

Does the cap on the methanol bottle have a teflon liner?

If so that could give fluctuating amounts of the interference depending on how much contact the methanol has with the liner in each bottle.

They do appear to have a PTFE liner. I'll be looking more into this. Thank you so much.