I am looking for a GC method for determination of small amounts of Maleaic Anhydride in Maleic Acid.
Does anybody know a GC column that is able to perform this separation ?
By bill tindall on Sunday, March 11, 2001 - 07:54 pm:
I have no experience with maleaic anhydride but lots with acetic anhydride which should be similar. At least with acetic anhydride you can not do the analysis by gc. During the separation there is equilibration between acid and anhydride, so what elutes is not what was injected. To test for this possibility, look closely at the baseline between the acid an anhydride peaks. If the baseline is elevated, or better yet look with a mass spectormeter for acid/anhydride between peaks, then the species are equilibrating during the separation. One possibility is to react the anhydride with something, for example an amine like butyl amine. With luck, in your dilute anhydride case, a single subsituted amide will result which can be readily measured by gc. Alternatively, this analysis may be possible by reversed phase lc (see J. Chromatogr, 868 (2000)41.) Reversed phase lc works quite well for acetic anhydride. I think the Liu reference cited in this paper did maleaic.
By Beppe on Monday, March 12, 2001 - 08:47 am:
Thank you for this valuable information. I will look for the HPLC method.
By Anonymous on Monday, March 19, 2001 - 11:08 am:
My experience with maleic anhydride has always required derivatization...usually to the silyl esters. Look for something besides BSTFA for your samples...I think the maleic may coelute with the BSTFA but the acid should separate.
By juris on Tuesday, March 20, 2001 - 01:01 am:
I am looking for a GC/MS method for determination
of glucose, mannose, galactose and fructose.
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