Silylation method for GC

Chromatography Forum: GC Archives: Silylation method for GC
Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Friday, May 2, 2003 - 10:05 am:

Hi,

I am planning on derivitising samples for analysis of chlorinated phenols using BSTFA/TMS. How exactly is this performed? From the literature, it appears that you just add the neat silylating reagent to your extract, allow to react and inject. Is this so? Is a solvent exchange not required after silylation?

Thanks.

PCB


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Friday, May 2, 2003 - 11:43 am:

You are correct about the literature. Just be certain you are using a liquid phase that does not react with the silylating reagent, ie Carbowaxes. Usually an excess is used for complete reaction. The unreacted reagent is volatile and usually elutes before any derivatized analyte. Note that you will have to clean your FID detector more often with these reagents if you are using packed columns.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By Anonymous on Friday, May 2, 2003 - 12:16 pm:

We usually trimethylsilylate with sample dissolved in DMF or pyridine, then adding the BSTFA, and shaking. Hydroxy groups and phenolics derivatize quickly, and are ready for injection into GC. We usually use HP-1 or HP-5 columns, with both FID and MS detection.


Top of pagePrevious messageNext messageBottom of pageLink to this message  By vijayaragavan on Friday, July 18, 2003 - 05:05 am:

hai,
bsa+hmds mixture will also help for the purpose and hp-50+ will do separate some isomers. usually silylation quickly happen and using mdc may help keeping moisture away. the cleaning fid oftern is mandatory.
vijay
india


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