| The corn samples were pretreated by Microwave Digestion Method, and lead, cadmium, mercury, arsenic was detected by Atomic Fluorescence Spectrometry (AFS) and Graphite Furnace Atomic Absorption Spectrometry (GFAAS) respectively. Digestion and instrumental parameters had influence on the heavy metal detection were investigated from the mathematical statistics method was used to get optimum detection conditions of different elements.The influence on digestion and recovery rate of lead and cadmium was contrasted microwave digestion with wet digestion; the effect of different reagent proportion on digestion and detection results was discussed; GFAAS determination parameters of lead and cadmium were optimized. The optimum conditions:the spectral bandwidth of 0.4nm, a negative high voltage is 411.00V, the lamp current is 2.0mA and the background correction is Zeeman correction.The parameters of microwave digestion were optimized by Orthogonal Test and Response Surface Method. The influence on digestion and determination of mercury by different reagent was discussed. The optimal conditions for:negative high voltage is 250V, atomizer height is 10.0mm, the lamp current is 35 mA and the carrier gas flow rate is 450 mLˇmin-1, shielding gas flow rate of 900 mLˇmm-1.The influence on the hydride generation efficiency and fluorescence intensity of arsenic by negative high voltage, lamp current, carrier gas was discussed. The optimum condition for the negative high voltage is 270V, atomizer height is 9.0mm, the lamp current is 60mA and the carrier gas flow rate is 400 mLˇmin-1, shielding gas flow rate is 800 mLˇmin-1.Consistencies of lead, cadmium, mercury, arsenic were detected under the optimum conditions and the detection quality control was be tested by Methodological. |
PDF Full Text Request