Objective To compare the two digestion methods of ammonium persulfate and the mixed acid system of nitric acid,sulfuric acid,and perchloric acid in determining total arsenic in urine by digestion-atomic fluorescence spectrometry.Methods Urine samples were digested by the mixed acid system of nitric acid,sulfuric acid,and perchloric acid and saturating ammonium persulfate at 310℃for 1 hour,then thiourea-ascorbic acid was added to reduce the sample,and the samples were placed in the atomic fluorescence spectrometry analyzer for determination.Results Within the range of 1.00-20.00 μg/L for the content of arsenic,the standard curve regression equation was y=106.587x-11.979,with a correlation coefficient of>0.999 0.The digestion method of the mixed acid sys-tem had a precision of 2.06%-3.03%,an average spike recovery of 101.2%-104.3%,and a detection limit of 0.012 μg/L.The saturating ammonium persulfate digestion method had a precision of 3.31%-4.05%,an average spike recovery of 97.9%-101.6%,and a detection limit of 0.006 μg/L.Conclusion The accuracy and precision of both methods meet the requirements in Determination of arsenic in urine by hydride generation atomic fluorescence spectrometry(WS/T 474-2015),and the two methods are suitable for large-scale determination of total arsenic content in urine.
维普
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