王水浸提-原子荧光法测定土壤中砷方法改进

比较了王水(1 1)和王水水浴浸提,原子荧光法测定土壤中砷,结果表明王水(1 1)水浴浸提法不适合土壤全砷的测定,对GSS-7检出率只有33%,后者对砷测较理想,对GSS-3,GSS-7,GSS-8 3种标准物质的检出率在95%~101%之间。同时试验了预还原剂(硫脲-Vc)的正确加入步骤,结果表明,将消煮液全部还原非常重要,否则会使结果偏低10%以上。

Method improvement of arsenic in soils extracted using aqua regia by HG-AFS

The methods of aqua regia(1 1) and aqua regia extraction in hot water were used to study the effects on total arsenic(As) in soils and the As was tested by the atomic fluorescence spectrometry(AFS).The results showed that aqua regia(1 1) extraction method was not suitable for the total As determination in soils and the test percent only had 33 % from the total As contents in GBW07407(GSS-7).The latter method was much better,and the test percents were between 95 %-101 % in GSS-3,GSS-7,GSS-8 samples.At the same time,the correct adding process of pre-reductant agent(Thiourea Vc) was studied.The results showed that it was very important to reduct the total digestion solution,otherwise the As tested would be less than 10 %.