title: Linear one-step assay for the determination of orthophosphate.
abstract: A rapid one-step spectrophotometric assay for orthophosphate that requires a single stable reagent solution is presented. The reagent solution, an aqueous mixture of ammonium molybdate and zinc acetate at pH 5.0, produces a stable complex with orthophosphate that absorbs strongly in the near-visible region of the light spectrum. Response to concentration of phosphate was linear up to 300 microM phosphate with a molar absorptivity of 7200 M-1 cm-1 at 350 nm. The mild conditions for phosphate determination employed in this method are unique, making it particularly suitable for the assay of orthophosphate in the presence of labile organophosphates.
mesh_terms: D000085:Acetates; D019342:Acetic Acid; D001221:Aspartate Carbamoyltransferase / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008982:Molybdenum; D010710:Phosphates / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D000085:Acetates; D010710:Phosphates; D008982:Molybdenum; D001221:Aspartate Carbamoyltransferase; C022175:ammonium molybdate; D019342:Acetic Acid