Has anyone used PIC reagent to assay Vitamin C together with other Vitamin Bs at the same time by HPLC-UV detector? Vitamin C does not seem to be stable and decreasing during the run.
Also when using the solube form of B2 (riboflavin sodium phosphate) many peaks were detected due to defferent retentions of the various of di-and mono- phosphates-how to assay so many peaks?
Please advise.