Efficient Determination of Lead, Chromium and Cadmium in Sauropus androgynus Sample with Backflow Environment Friendly Digestion-GFAAS Method

ZHAO Min;ZHOU Cong;DENG Aini;FAN Qiong;CAI Fufeng;GAO Lihua;Analysis and Testing Center / Tropical Agricultural Products Quality Supervision,Inspection,Analysis and Testing Center of Ministry of Agriculture, CATAS;

backflow environment friendly digestion;;graphite furnace atomic absorption;;lead;;chromium;;cadmium;;Sauropus androgynous

Use environment friendly efficient sample digester to digest Sauropus androgynus sample, then use graphite furnace atomic absorption spectrometer(GFAAS) to measure lead, chromium and cadmium concentrations in the test solution, to obtain content of the three elements in the sample. Baseline value, digestion temperature, digestion time, acid recovery rate, and method reliability experiments are respectively conducted during research process. The results show that the baseline value measured using this digestion method is lower than that measured using conventional digestion method, and test precision is higher; Digestion time is shortened to 0.5-1.0 hours from more than 12 hours of conventional method(with cover), greatly improving the analysis efficiency; 35%-75% nitric acid can be recycled during experiment process, which decreases the pollution of nitric acid volatile substance on atmospheric environment; All analysis results of national standard substances measured(cabbage and celery) are within the scope of standard values, with relative standard deviation less than 10.0%, and the analysis results are accurate and reliable.