土壤总砷测定前处理方法探讨

采用加标回收方法比较研究了5种土壤总砷测定的前处理方法(分别为浓HNO3-浓H2SO4-HC1O4法、王水法、浓HNO3-浓H2SO4-V2O5法、浓HNO3-浓H2SO4-V2O5Ⅰ法和浓HNO3-浓H2SO4-V2O5Ⅱ法),结果表明,5种前处理方法的加标回收率在89.9%～102%之间,变异系数在0.56%～5.27%之间。其中,浓HNO3-浓H2SO4-V2O5Ⅰ法处理,土壤所用消解时间40min左右,其回收率较高,在98.5%～99.1%之间,变异系数较小,在0.56%～0.85%之间;该前处理方法具有消解时间最短、加标回收率和精密度高及重现性最好的特点,优于其他4种前处理方法,可作为推荐方法应用。

Study on the Pretreatment for Determination of Soil Total Arsenic

A recovery experiment by adding standard arsenic to soil was conducted to compare the five kinds of pretreatment methods for determination of soil total arsenic(HNO3-H2SO4-HC1O4 method,aqua regia method,HNO3-H2SO4-V2O5 method,HNO3-H2SO4-V2O5Ⅰmethod and HNO3-H2SO4-V2O5Ⅱmethod).Results showed that the recovery of standard addition of the 5 methods varied in the range of 89.9% to 102%,while their coefficients of variation were 0.56% to 5.27%.Among these pretreatment methods,the HNO3-H2SO4-V2O5Ⅰmethod had a higher recovery of standard addition(98.5%-99.1%) and lower coefficient of variation(0.56% ~ 0.85%),while its digestion time was about 40 minuets.Compared to the other 4 pretreatment methods,the HNO3-H2SO4-V2O5Ⅰmethod had the shortest digestion time,highest recovery of standard addition,highest precision and best reproducibility,therefore could be applied as the recommended method.