Effects of filter-paper adsorption and desorption on the spectrophotometric and radiochemical measurement of phosphate in filtered solutions

Abstract

Solutions are commonly filtered through standard laboratory filter-papers prior to measurement of phosphate. Experiments with ³²P show that these papers can interfere with the determinations by either releasing phosphate into, or absorbing it from, the solutions, especially at concentrations of less than 1 µg cm^–3 of ³¹P. Correction for this interference is difficult owing to variability within the over-all trends, but ameliorative procedures are proposed.