Abstract:Objective:To establish the method of determination of cadmium in rice by direct dilution injection graphite furnace atomic absorption spectrometry.Methods:Crushed rice was diluted by mixture of 0.5% nitric acid and 0.1% Triton.Then the diluent was well shaken for further test.NH4H2PO4+Mg(NO3)2 were chosen as the matrix modifier,while the Zeeman effect background deduction method was adopted.The samples were subjected to one-step ashing method(argon),and two-step ashing method(argon+air),respectively,to create external standard calibration curves.The standard addition method was used to determine cadmium content in rice.The results showed that the RSD(N=6)of three methods were 1.78%,3.29%,and 0.62%,while the recovery rates were 114.7%,103.9%,and 102.5%.The detection limits were 0.025,0.031,and 0.035 μg/L.After T test of pairwise comparison,no significant difference was shown between two-step ashing method and standard addition method,and the accuracy and precision meet the requirements for determination well.Conclusion:As a simple,rapid and non-polluting method,the direct dilution injection graphite furnace atomic absorption spectrometry can be used for the determination of cadmium content in rice precisely and accurately.