ABSTRACT
A mild rapid method for the determination of Pb in grain was established by diluted acid extraction and direct sampling detection with graphite furnace atomic absorption spectrophotometer(GF-AAS). Some factors, such as the grain size, nitric acid concentration, extraction time, solid, liquid proportion, and the instrument conditions were optimized. The results indicated that, at room temperature, the extraction rate of Pb in grain by diluted nitric acid was between 92. 14% and 94. 75%, and the average recoveries of Pb in grain extract reached 91. 65%-94. 58%, the precision of method was less than 5%, and the method detection limits and quantification limits were 0. 64 μg/L and 2. 14 μg/L, respectively, meanwhile, the extraction time was shorten to no more than 30 min. Compared with the results pretreated by microwave digestion and determined by GF-AAS, the detection values obtained by diluted acid extraction had no significance difference (p<0. 1).
