EDXRF determination of impurities in potassium dihydrogenphosphate single crystals and raw materials

Abstract

A fast and simple preconcentration procedure for recovering various cation impurities from potassium dihydrogenphosphate (KDP) single crystals and raw materials, followed by energy-dispersive X-ray fluorescence analysis (EDXRF), is described. The technique is based on the adsorption of metal 8hydroxyquinoline complexes from aqueous solutions of KDP on activated carbon, separation of the concentrate on a Nuclepore filter and subsequent determination by EDXRF. To fix activated carbon powder on a filter surface, an amount of 1-hexadecanol is added to the KDP solution during the preconcentration procedure. The optimum conditions for the best recovery of the impurities were established. It was shown that a preconcentration factor of 100 can be achieved and the detection limit for a number of elements was down to 0.01 µg g −1 . The relative standard deviations were 6-17% for element concentrations of 0.2 µg g −1 .The method was successfully applied to the determination of Fe, Co, Cu, Ni, Zn, Mn, Ti and Bi in KDP single crystals and raw materials.

Atomic spectrometry update—X-ray fluorescence spectrometry

“…Detection limits for Co, Cu and Zn in seawater were 1.53, 0.31 and 0.21 mg kg À1 , respectively. Belikov et al 183 described a fast and simple preconcentration procedure for recovering various cation impurities from potassium dihydrogenphosphate (KDP) single crystals and raw materials, followed by EDXRF analysis. The technique was based on the adsorption of metal-8-hydroxyquinoline complexes from aqueous solutions of KDP on activated carbon and the separation of the preconcentrate on a Nuclepore filter.…”

Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials

“…194 The results from both methods were compared and were found to be in agreement; especially when As was used as an internal standard during the XRF measurements. Impurities in potassium dihydrogen phosphate were determined using EDXRF by Belikov et al 195 Sample was diluted in water, 8-hydroxyquinoline added and the metal-8-hydroxyquinoline complexes formed were retained on activated carbon, separated onto a Nuclepore filter and then the impurities determined using EDXRF. To fix the activated carbon to the filter, 1-hexadecanol was added to the sample solution during the preconcentration procedure.…”