微波消解-火焰原子吸收光谱法测定环境土壤中的总铬

Determination of Total Chromium in Environmental Soil by FAAS with Microwave Digestion

应用微波消解-火焰原子吸收光谱法测定环境土壤中总铬的含量。土壤样品经HNO3+H2O2微波消解体系消解后,采用氯化铵作为基体改进剂,用原子吸收分光光度计在波长357.9nm,富燃烧性(还原性)火焰中测定土壤中的铬。铬含量在0—2.00mg/L范围与吸光度呈良好的线性关系,线性相关系数r=0.9993,最低检出限为5.0mg/kg。用该方法测定了500多个环境土壤中总铬,相对标准偏差小于5.2%,测定的环境标准土壤中总铬均在允许范围内。

A method for the determination of the content of total chromium in the environmental soil was established by flame atomic absorption spectrometry with microwave digestion.The samples were digested by HNO3＋H2O2 microwave digestion system with NH4Cl as the matrix modifier,and chromium in the soil was determined on rich flammability（reducing） flame at wavelength of 357.9nm by atomic absorption spectrophotometer.There was a good linear relationship between chromium concentration and absorbency in the range of 0—2.00mg/L,with linear correlation coefficient r of 0.9993 and detection limit of 5.0mg/kg.This method was applied to detecting more than 500 environmental soil,and the relative standard deviation was less than 5.2%,the determination of environmental standards are within the allowable range of soil.