By Anonymous on Thursday, June 17, 2004 - 02:20 pm:

Is anyone in here familiar with EPA Method 548.1? I am using a DB-624 column and an FID detector. I am not seeing any peaks, though. The column was working fine with TPH samples, but I can't seem to get any endothall or internal standard peaks. Any suggestions would be appreciated.

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By B.Buglio on Tuesday, June 22, 2004 - 05:01 pm:

Do you get a peak for the calibration std dimethyl
endothall?

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By Anonymous on Wednesday, June 23, 2004 - 11:20 am:

I calibrated using standards that were extracted; I also added an internal standard. I did not see anything consistent in overlays of the chromatograms.

I was advised to order an endothall standard that does not have to be extracted (the dimethyl endothall) as a reference point for the extracted curve points.

Hope that will work.

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By B.Buglio on Wednesday, June 23, 2004 - 04:00 pm:

Your headed in the right direction wrt
troubleshooting the problem - good luck