氢化物发生-原子吸收光谱法测定日用洗涤剂中砷和汞方法的改进
Modification of the HG-AAS Determination of Arsenic and Mercury in Daily Detergents
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摘要: 按《化妆品卫生规范》测定日用洗涤剂中砷和汞含量时,对样品前处理方法作如下改进:① 微波消解时,采用梯度升温进行消解;② 所得消解液加入氨基磺酸去除氮氧化物,以消除其对砷和汞测定的干扰。按改进后的方法,砷和汞的质量浓度分别在18,60 μg·L-1以内与吸光度呈线性关系,检出限(3s/k)分别为1.7,0.4 μg·L-1。以空白洗涤剂样品为基体,用标准加入法做回收试验,测得砷和汞的平均回收率分别为100%,99.5%;测定值的相对标准偏差(n=6)分别为1.2%,1.5%。Abstract: In the determination of As and Hg in daily-use detergents by “Hygienic Standard for Cosmetics”, modification for pretreatment of sample was made in 2 respects: ① the sample was digested under programmed temperature control; ② aminosulfonic acid was added into the sample solution obtained to eliminate the interferences of oxides of nitrogen. Linear relationships between values of absorbance and mass concentration of As and Hg were kept in the ranges within 18, 60 μg·L-1, with detection limits (3s/k) of 1.7 μg·L-1 and 0.4 μg·L-1 respectively. Recovery and precision were tested with blank sample by standard addition method, giving values of average recovery of 100% for As and 99.5% for Hg, and values of RSD′s (n=6) of 1.2% and 1.5% respectively.