RESUMO
Objective:To establish a direct and rapid method for direct determination of arsenic in urine by inductively coupled plasma mass spectrometry (ICP-MS).Methods:The newly collected urine samples were diluted directly with pure water without pretreatment. The total arsenic content in urine was determined directly by ICP-MS. The method was studied from the aspects of linear range of standard curve, correlation coefficient, detection limit, precision and accuracy.Results:The concentration of arsenic in urine was in the range of 0 - 200 μg/L, the ratio of arsenic to germanium was in good linear relationship with arsenic concentration, the correlation coefficient was 0.999 5 - 0.999 9 ( n = 6), the lowest qualitative and quantitative detection limits of arsenic in urine were 0.66 and 1.94 μg/L(the sampling volume was 0.50 ml), respectively. Five urine samples with different arsenic concentrations were tested for intrabatch and inter batch precision with RSD ranging from 1.51% to 6.84% and 1.85% to 5.03%, respectively. The total arsenic of urine samples from the Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention was determined with this method, and the results were within the range of the published consensus value. The recovery rate of 4 urine samples with arsenic concentration range 3.19 - 89.36 μg/L was 99.25% - 103.67%, and the total average recovery rate was 101.51%. Conclusions:Application of ICP-MS method to detect arsenic content in urine, urine samples can be directly injected to realize the automation of injection, detection process and result analysis. The test parameters such as sensitivity, precision and accuracy of the method meet the requirements of the development of biological sample detection method and are suitable for rapid and direct determination of total arsenic in urine.