The determination of arsenic,cadmium,lead and chromium in fertilizer by inductively coupled plasma mass spectrometer method
Seven different fertilizer samples were selected for digestion by nitric acid-hydrochloric acid(aqua regia).The contents of heavy metals such as arsenic(As),cadmium(Cd),lead(Pb)and chromium(Cr)in the digestion solution were determined by helium collision mode using an inductively coupled plasma mass spectrometer(ICP-MS)method.The results showed that:based on the solid weight of 0.2 g and the constant volume of 50 mL,the detection limits of Cr,As,Cd and Pb were 0.018,0.008,0.005 and 0.021 mg/kg,respectively,and the limits of quantification were 0.061,0.025,0.016 and 0.069 mg/kg,respectively.According to the liquid weight of 1.0 g and the constant volume of 50 mL,the detection limits of Cr,As,Cd and Pb were 0.004,0.002,0.001 and 0.004 mg/kg,respectively,and the limits of quantification were 0.012,0.005,0.003 and 0.014 mg/kg,respectively.The relative standard deviation of Cr,As,Cd and Pb(n=6)were 3.8％-16.8％,3.9％-56.5％,0-25.7％and 4.2％-24.5％,respectively.The recoveries were 67.4％-122.0％.Samples of different fertilizer types were extracted from four laboratories for laboratory comparison,and the analysis showed that there was consistency between the test values of all the participating laboratories.After the outliers were removed by the Cochran test and the outliers were retained,the Grubbs test was applied to the unit average after passing the Cochran test,and no single or pairs of outliers or outliers were found for each element.The precision and accuracy of the method meet the requirements.Conclusion suggested that ICP-MS could be used for the determination of As,Cd,Pb and Cr in fertilizer.
heavy metalinductively coupled plasma mass spectrometrylaboratory comparison
万方数据
维普
