Determination of the zeolite and silicate content in detergent products by wavelength-dispersive x-ray fluorescence spectrometry

摘要

A method was developed for the determination of zeolite and silicate in detergent products and raw materials by wavelength-dispersive x-ray fluorescence (WDXRF) spectrometry, Al, Si and Na were measured after fusion of the sample with a mixture of lithium tetra- and metaborate. The influence of the fusion conditions, the stability of the glass beads and calibrations using practical and calculated a values were studied. The WDXRF method was validated by analysing laundry detergent products and zeolite and sodium silicate raw materials. The detection limit was 0.012% for Al, 0.010% for Si and 0.020% for Na (= 0.05% anhydrous zeolite and 0.08% sodium disilicate), The precision was dependent on the homogeneity of the sample. For Al, Si and Na in zeolite, the long-term precision was 0.08, 0.09 and 0.10%, respectively. For detergent powders, maximum relative standard deviations of 0.2, 0.3 and 0.7% were found for Al, Si and Na, respectively. No significant difference was found between the WDXRF method and the reference methods (titration, gravimetry, flame atomic absorption spectrometry), Copyright (C) 2000 John Wiley & Sons, Ltd. [References: 6]