MPT-AES法测定老酸奶中铅和铬

Determination of plumbum and chromium in the yogurt by MPT-AES

用微波等离子体炬（MPT）为激发光源，氩气为等离子体工作气体，用气动雾化进样，采用标准曲线法研究了微波等离子体炬原子发射光谱法（MPT—AEs）测定老酸奶中铅和铬的方法。详细考察了Pb和Cr的最佳分析谱线波长、微波前向功率、栽气流量、工作气流量等实验参数对测定强度的影响。同时考察了酸浓度和共存离子对铅和铬测定的影响。在最佳条件下测得铅和铬的检出限分别为4．7μg／L和4．8μg／L，线性范围分别为0．1-100mg／L和0．5-50mg／L，精密度分别为3．85％和2．10％，加标回收率分别为98．2％-101-3％、98．5～99．2％。

Using microwave plasma torch （MPT） as excitation light source, argon as support gas,the sample solution was in troduced in to a pneumatic atomizer system by the standard curve method. The determination of plumbum and chromium in yogurt by microwave plasma torch atomic emission spectrometry （MPT-AES） was studied.The detection conditions, including analytical line, microwave forward power, flow rate of carrier gas and support gas to the emission strength of elements of plumbum and chromium were optimized. The effects of acid concentration and coexistent ions on the detections were investigated in detail.The results showed that the detection limits of plumbum and chromium were 4.7 p,g/L,4.38 μg/L, the precisions were 3.85%,2.10%, and the linear ranges were 0.1-100 mg/L,0.5-50 mg/L, the recov- ery were 98.2%-101.3%,98.5%-99.2%, respectively.