Determinação de arsênio em águas contaminadas usando fluorescência de raios-X por energia dispersiva

Abstract

This work proposes a simple, fast and inexpensive method to determine As in natural waters, using X-ray fluorescence. 50 μL of each sample containing 100 mg L-1 of yttrium as internal standard were deposited over a 2.5 μm thickness Mylar™ film. The samples were dried at 50°C for 2 h. X-ray spectra were obtained using an EDXRF apparatus. The accuracy was determined by analyte addition/recovery and by comparison with Hydride Generation Atomic Absorption Spectrometry (HG AAS). A recovery of about 100% was obtained and the results were in good agreement with HG AAS. The method showed a relative standard deviation of 6.8% and a detection limit of 10.5 μg L -1 of As.