8260 P&T chloroform

[MichaelVW]

I'm seeing some blank hits for chloroform of about 1 ppb.

We're used to seeing a little bit of DCM and acetone in our blanks, which I attribute to using them as extraction solvents in the next room. But we don't have chloroform anywhere.

Anyone seen this before? I'm wondering about active sites in the transfer line breaking other things down, or maybe a sign that the trap is getting old.

[DReggio]

Chloroform can commonly come from the DI system. I monitor it and change the filters as it creeps up.

You can boil some DI and see if it decreases.

[OldGCguy]

The question is - is the chloroform present in the blank water or is it formed in the P&T procedure? Try some purchased high quality water - Perrier, San Pellegrino or similar - should be free of contamination in measurable quantities. Or, as has been suggested, try distilled water rather than de-ionized.