I need to quantifier the H3PO3 content in a diammonium phosphate.
I did a generic method for reducing substances by iodine titration, but I'm looking a specific method for understand if the phosphite is really present in my product.
I tried a GC-MS method by esterification the H3PO3 with Methanol and it work quit good on the standard but not in this kind of matrix (the spike recovery is zero).
Anyone knows a method for resolve my problem?