- Fiske and Subbarow's method
- 1. (for acid-soluble phosphorus in blood) destroy organic matter by heating with sulfuric and nitric acids, precipitate the phosphates as magnesium ammonium phosphate, and reduce the precipitate with para-amino-naphthol-sulfonic acid. Compare the blue color with a standard phosphate solution. 2. (for inorganic phosphates) the phosphates are precipitated as ammonium phosphomolybdate. This is then reduced by para-amino-naphthol-sulfonic acid and the blue color compared colorimetrically with a standard solution.
Medical dictionary. 2011.