Residue analysis problem; DDT transformation to DDD

Chromatography Forum: GC Archives: Residue analysis problem; DDT transformation to DDD
Top of pagePrevious messageNext messageBottom of pageLink to this message  By Emad on Wednesday, October 2, 2002 - 10:00 am:

Hi everybody,
I am working in pesticide residue analysis. We are analysing about 35 pesticides using Luke method and determination with GC-ECD, we use HP-6890 with HP-PAS 1701 and PAS 5 capillary column. The problem is that we notice a transformation of p,p-DDT into p,p-DDD. When we injected p,p-DDT on GC-FID under the same conditions of temperature program and column types and also HPLC-UV we get only single peak for DDT. Please any response about the reason of such transformation will be appreciated.
Emad


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Thursday, October 3, 2002 - 09:10 am:

Your column and liner are very active, therefore you have problem with thermally labile components such as ddts and particularly endrin. You have to obtain a very low activity liner/column. Normally, endrin is a good test for activity or try cool oncolumn injection.


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