【摘要】 建立了微波辅助提取,采用氢化物发生原子荧光光谱法不进行价态分离,直接测定土壤中As(Ⅲ)和As(Ⅴ)的方法。通过加入抗坏血酸作为抗氧化剂,以磷酸溶液、L-半胱氨酸分别为提取剂和还原剂,在不还原与还原两种情况下分别进行测量,根据荧光强度与As(Ⅲ)和As(Ⅴ)的质量浓度关系方程式计算提取液中它们的质量浓度。对实验条件进行优化后,As(Ⅲ)、As(Ⅴ)的方法检出限均可达到0.05μg.g-1,实验精密度(RSD,n=11)分别为1.3%和2.1%,样品加标平均回收率分别为As(Ⅲ)为93.2%~110.0%,As(Ⅴ)为92.6%~104.0%。该方法不需要高效液相色谱等大型设备、简单可靠、易于操作、分析速度快、精密度高,具有在各分析测试实验室推广应用价值。方法已用于实际土壤样品中不同价态无机砷质量分数的测定。更多还原

【Abstract】 A non-chromatographic speciation method was developed for the determination of As(Ⅲ) and As(Ⅴ) in soil samples with microwave-assisted Extraction.The soils were extracted using phosphate as extractant in combination with ascorbic acid.The addi-tion of ascorbic acid was used to prevent the oxidation of As(Ⅲ).The L-cysteine was selected as reductant.Speciation was made using proportional equations corresponding to two different measurement conditions.The limits of detection of the method was 0.05 μg·g-1.The relative standard deviations of As(Ⅲ) and As(Ⅴ) were 1.3% and 2.1%,respectively.The recoveries in the determi-nation of As(Ⅲ) and As(Ⅴ) were in the range of 93.2%~110.0% and 92.6%~104.0%,respectively.This method was simple and reli-able,and easy to operate We do not need large instrument to measure the As(Ⅲ) and As(Ⅴ) applying this method in the analytical laboratory.The method has been successfully applied to the extraction and determination of As(Ⅲ) and As(Ⅴ) in real soil samples.更多还原