新型分散液液微萃取-石墨炉原子吸收光谱法测定地质样品中银

摘要

GFAAS was applied to the determination of Ag in geological samples with novel dispersive liquid liquid microextraction using octanol as extractant.The optimized conditions found were as follows:① amount of octanol(extraction solvent)was 0.30 mL;②amount of 2 g·L-1DPTU(complexing agent)ethanol solution was 1.0 mL;③ amount of ethanol(dispersant)was 10 mL;④ pH of sample solution was 3.0-7.0;⑤ ashing temperature was 500℃;⑥atomization temperature was 1 700℃.Linear relationship between values of absorbance and mass concentration of Ag was kept in the range of 0.02-0.50 μg·L-1,with detection limit(3s)of 4.7 pg. The proposed method was applied to the analysis of geological samples,giving results in consistency with the certified values with RSD′s(n= 5)in the range of 3.2%-6.8%.%采用基于正辛醇为萃取剂的新型分散液液微萃取-石墨炉原子吸收光谱法测定地质样品中银的含量.优化的试验条件如下:① 萃取剂正辛醇的用量为0.30 mL;② 2 g·L-1对称二苯基硫脲(络合剂)乙醇溶液的用量为1.0 mL;③分散剂乙醇的用量为10 mL;④样品溶液的pH为3.0~7.0;⑤ 灰化温度为500 ℃;⑥ 原子化温度为1700 ℃.银的质量浓度在0.02~0.50 μg· L-1内与其对应的吸光度呈线性关系,检出限(3s)为4.7 pg.方法应用于地质样品的分析,测定值与认定值相符,测定值的相对标准偏差(n= 5)为3.2%~6.8%.