同位素稀释-多接收电感耦合等离子体质谱法测量国际比对红酒样品中铅的含量

采用同位素稀释-多接收电感耦合等离子体质谱法(ID-MC-ICPMS)测量了国际比对红酒样品中铅的含量。因为红酒中铅含量仅有约3 ng/g,而流程空白却有0.3 ng,使本次测量几乎达到了方法检测限。比对结果表明,采用同位素稀释质谱法容易取得较一致的结果。在不确定度分析中将与方法相关的各项影响因素都做了定量分析,实际上,流程空白给实验结果精密度造成了很大的影响,从而增大了不确定度。因此,本方法中流程空白的控制在超低浓度样品分析中起到至关重要的作用。

Determination of Lead In Red Wine for CCQM-K30 International Comparison by Using ID-ICPMS

The content of lead in red wine for CCQM-K30 international key comparison is determined by using isotope dilution mass spectrometry(IDMS).This test almost reach detect limit of the method because the content of lead in red wine was only 3 ng/g and the procedure blank was about 0.3 ng.The comparison results indicate that it is easy to achieve agreements using IDMS.In uncertainty analysis,all of the factors about IDMS method were considered.But,procedure blank took great inference to experiment precision and enlarged the total uncertainty.Therefore the controls of procedure blank were very important for the analysis of ultra-trace concentration of samples.