The determination of phosphate in detergents by cool-flame emission spectroscopy

Abstract

The total phosphate content of detergent materials is determined by measurement of the emission of the HPO molecular species at wavelength 528 nm in a cool hydrogen-nitrogen diffusion flame. Preliminary treatment with cation-exchange resin is necessary to remove interference by metals. Analytical results on detergent samples containing up to 20 per cent. of phosphates (expressed as P₂O₅) indicate a precision of the order of 2 to 4 per cent. for the method.