硝酸—高氯酸与王水回流法在AAS测定中的比较

王水迴流法消化污泥和土壤,较常规的王水消化法可多提取10%的重金属.本实验应用1:1的硝酸—高氯酸和铝制消化器对128个土壤样品镉、铬、铜、铅、锰、镍和锌7个元素进行了测定,并与王水迴流法所测数据进行了比较.统计结果表明,两种方法所得结果具有极显著的相关性,然而是截然不同的两组数据.除锌外,用硝酸—高氯酸法所得值明显高于王水迴流法,可在实验室广泛使用.在铬的测定中,钠、钾、镁、钙、锰、铝和铁做为潜在的干扰因素及不同火焰状况对测定的影响被加以探讨.结果表明,使用贫氧化亚氮—乙炔火焰不会产生正、负干扰.

The Comparison of HNO_3-HClO_4 Digestion with Aqua-Regia Reffuxing Procedure in Measuring by AAS

Digesting sludge and soil samples by refluxing procedure with aqua-regia can extract to of heavy metals more tha n that by ordinary aqua-regia digestion . The present experiment investigated digestion procedure with nitric-perchloric acid( 1 : 1 ) using an aluminium digestion block. A range of 128 siudge-treated soil samples were analyzed for seven elements: Cd , Cr , Cu , Pb , M n, Ni , Zn, and results have been compared with aqua- regia. The correlation coefficients imply clearly that the two digestion methods have a close correlation but the T tests denote that they give significant results. Except Zn , the extracting coefficients for these elements are obviously higher than those by using refluxing procedure with aqua-regia.Also, seven elements : Na , K , Mg , Ca , Mt, , Al , Fe,as potential interferences and different flames have been studied in the determination of Cr . The result showed that using fuel -lean dinitrogen oxide-acetylene flame would not produce neither positive nor negative interferences .