用微波消解法处理样品,石墨炉原子吸收光谱法测定酱油中铅含量.采用在标准溶液中添加相同浓度的氯化钠以抵消氯化钠对测定的干扰,用磷酸二氢铵和硝酸镁混合溶液作为基体改进剂.铅的质量浓度在5.0~40.0 μg·L-1范围内与其吸光度呈线性关系,检出限(3s/k)为16 pg,相对标准偏差(n=7)为3.32%.应用此法测定酱油样品,加标回收率在91.0%~98.6%之间.

The sample of soy sauce was pretreated by microwave assisted sample digestion,and lead in the sample solution was determined by GFAAS. Interference of NaCl in sample solution was offset by addition of nearly same amount of NaCl to the standard solutions in preparation of standard curve. Mixed solution of NH4H2PO4 and Mg(NO3)2 was used as matrix modifier. Linear relationship between values of absorbance and mass concentration of lead was obtained in the range of 5.0-40.0 μg·L-1,with detection limit (3s/k) of 16pg and RSD (n=7) of 3.32%. The proposed method was used to the analysis of soy sauce,giving values of recovery in the range of 91.0%-98.6%.