粮食中镉、铅含量快速测定的试验设计OA

To address the issues of complex pretreatment procedures,time-consuming operations,and difficulties in meeting the requirements for on-site rapid detection of cadmium(Cd)and lead(Pb)in grains using traditional anodic stripping voltammetry(ASV),an analytical system based on ASV for the rapid determination of Cd and Pb in grains was established and optimized.Ammonium acetate+ammonium chloride+mercury was used as the supporting electrolyte,and 20%(V/V)nitric acid was employed as the extraction solution.The pretreatment process was simplified through vortex oscillation and centrifugation.Key parameters including the supporting electrolyte,extraction solution,and extraction time were systematically optimized.Matrix-matched external calibration was adopted to eliminate matrix effects,and the method was validated by comparison with inductively coupled plasma mass spectrometry(ICP-MS)as the reference method.The results showed that Cd and Pb exhibited good linearity in the concentration range of 0-500 μg/L.The limits of detection(LOD)for Cd and Pb in brown rice were 0.005,0.006 mg/kg,respectively,and those in corn were 0.011,0.012 mg/kg,respectively.The average recoveries ranged from 95.3%to 102.3%,with coefficients of variation(CV)between 3.16%and 10.20%.No significant difference was observed compared with the ICP-MS method by t-test(P>0.05).After optimization,the total time required for sample pretreatment and measurement was only 10 min.This study provides a reliable technical reference for the on-site rapid safety detection of staple grains.