AFS DETERMINATION OF ARSENIC AND MERCURY IN BIOLOGICAL SAMPLES-DIGESTION OF SAMPLE BY MICRO WAVE HEATING

Microwave heating of sample digestion was applied to the AFS determination of arsenic and mercury in biological samples.The sample was digested in polytetrafluoroethylene (PTFE) vessel with HNO3 and HClO4,and heated with microwave digestion instrument using the mode of gradient elevation of pressure.The sample solution obtained was made up to 25 mL with HCl(1+9) and used as mother solution for AFS determination of arsenic and mercury.Optimum working parameters of the AFS instrument were given in detail.Linearity range for the determination of arsenic was found to be 0 to 20 μg·L-1,and for mercury to be 0-16 μg·L-1,with their detection limits of 0.21 μg·L-1 and 0.06 μg·L-1 respectively.In the analysis of biological sample,recoveries of 100.5% for arsenic and 98.6%% for mercury were obtained,and RSD′s obtained were less than 4%.