By Anonymous on Thursday, March 25, 2004 - 12:36 am:
I need a HPLC method for vitamin C in infant formula
By Anonymous on Thursday, March 25, 2004 - 04:43 am:
We use a Prevail organic acids column from Alltech (5um 250 x 4.6mm) with a mobile phase of 0.08% formic acid in water at 1.0ml/min. Detection UV at 250nm. It works well. The thing is though we have no matrix problems which you might encounter with the infant formula. You have to remember also that ascorbic acid degrades very quickly in water so you have to prepare and inject immediately so you can't rack up a number of samples in an auto sampler. Hope that helps.
regards
John
By Fabiano on Wednesday, March 31, 2004 - 06:08 am:
U.S NIST method: they use Dithiothreitol for reduce all the dehydroascorbic acid to ascorbic acid before inject and to stabilize the standards and samples.
A NH2 column (250x4,6) with acid phase (~1% CH3COOH pH 2,5 in 75% ACN)will work as a weak anion exchanger, peak at 5 minutes, detection @245nm.