Determination of Iron on Cloths by Wavelength-Dispersive X-Ray Fluorescence Spectrometry

For textile detergency studies, a method was developed for the determination of iron on cloths by wavelength-dispersive x-ray fluorescence (WDXRF) spectrometry. Iron was measured directly on the cloths without prior sample pre-treatment. A linear calibration line was obtained for cloths with iron contents ranging from 0 to 15 000 mg kg-1. This calibration line can be used for different types of soiled cloths. The measured concentrations have to be corrected when the thickness of these cloths differs from that of the calibration cloths. The method was tested on various artificially soiled test cloths including cotton and polyester-cotton cloths treated with blood, clay and iron oxide. Results were found to be within ±6% relative of those obtained with inductively coupled plasma atomic emission spectrometry after digestion of the cloth in a microwave system. The detection limit was 3 mg kg-1. The short- and long-term precisions were 0.4 and 2.1% (RSD), respectively, at iron levels ranging from 250 to 11 000 mg kg-1. Copyright © 1999 John Wiley & Sons, Ltd.