Chromatography Forum

I work as an extractionist and analyst at an environmental lab and one of our most common methods is 525.2 drinking water analysis. In the past month we have been dealing with a previously unseen problem of apparent adipate contamination in our final results.

525.2 analysis is notoriously touchy and we've had to address other issues of contamination (phthalates mostly, and occasionally spike analytes that carry over for sometimes-unknown reasons) before, but the adipate issue is a new one. It is showing up frequently but inconsistently in our final results. At least three different experienced extractionists have had the same problem. We're aware that plastics and various personal products contain adipate, but there's nothing that's being used or introduced (as far as we know after discussing the issue painstakingly) that wasn't already in use in the months and years before this became a problem.

Does anyone have any suggestions, or memories of dealing with a similar problem? Any input would be appreciated.

A few more details would be in order.
You mentioned caryover which brings a few questions to mind:
1) what are your injector parameters. Could you be over loading the injector.
2) Injector maintenance ( if Agilent and have been overloading there can be lots of "junk" in the split vent line).
3) have you changed anything recently? ( solvents, extraction cartrides etc.)

I had a problem that drove me nuts for a while caused by phthalates in my ethyl acetate that " activated" my injection port after 10 or so injections.

When you inject solvent only, do you get peaks?