A rapid spectrophotometric estimation of individual phosphates and phosphonates: its application to chromatography of sugar phosphates and their phosphonate analogues.

A compound containing the -PO3H2 group (phosphoric acid, one of its monoesters, or an alkylphosphonic acid) may be rapidly assayed by the decrease it produces in the absorbance at 450 nm of a buffered acidic solution of Fe3+ and N(-3) [corrected]. The method has been used to follow chromatograms of sugar phosphates and their phosphonomethyl analogues.