Ammonium molybdate-stannous chloride determination of orthophosphate in the presence of triton X-100

A colorimetric method for the determination of orthophosphate in the presence of Triton X-100 and the extent of their mutual interference is presented. Effects of albumin and trichloroacetic acid on the reaction are also examined. The method is based on the very sensitive reaction developed for determination of orthophosphate by complex formation with ammonium molybdate followed by reduction with stannous chloride. The method allows determination of 0.005 μmol of orthophosphate in the presence of up to 0.5% Triton X-100 and as little as 0.3% ( v v) Triton X-100 in the absence of phosphate.