Odd 4-chloro-3-methylphenol tailing

[alpha]

I have seen an odd phenomenon with the analyte for method 8270. If successive runs of soil samples extracted by an ASE are run, the tailing for 4-chloro-3-methylphenol increases with each run. I have seen some tail for up to 2 minutes. But, this is not seen with extracted water samples. In fact, I can run a water sample immediately after a badly tailing soil extract and not see any tailing at all.

Has anyone else experienced this? If so, did you ever come to a reasonable explanation?

Thanks for the info.

[Peter Apps]

Most likely water vapour is temporarily deactivating active sites somewhere in the system.

Peter