A spectrophotometric method has been devised for measuring microgram levels of phosphorus in brazing alloys of gold or silver that contain high nickel concentration. Phosphorus in such alloys is normally measured by solid mass spectrometry, but the high nickel concentration produces a double ionized nickel spectral interference. The described procedure is based upon the formation of molybdovanadophosphoric acid when a molybdate solution is added to an acidic solution containing orthophosphate and vanadate ions. The optimum acidity for forming the yellow colored product is 0.5 N hydrochloric acid. The working concentration range is from 0.1 to 1 ppm phosphorus using 100 mm cells and measuring the absorbance at 460 nm. The sample preparation procedure employsaqua regia to dissolve the alloy and oxidize the phosphorus to orthophosphate. Cation exchange chromatography is used to remove nickel ions and anion exchange chromatography to remove gold ions as the chloride complex. Excellent recoveries are obtained for standard phosphorus solutions run through the sample procedure. The procedure is applicable to a variety of gold or silver braze alloys requiring phosphorus analysis.