微波等离子体炬原子发射光谱法测定葡萄酒中的铅

铅是重金属元素,因此食品中铅污染的控制对人体健康至关重要。文中用微波等离子体炬(MPT)为激发光源,氩气为等离子体工作气体,用气动雾化进样,研究了微波消解微波等离子体炬原子发射光谱法(MPTAES)测定葡萄酒中的铅元素的方法。详细考察了微波功率、载气流量、工作气流量、氧屏蔽气流量、硝酸浓度等实验参数对测定铅的影响,同时考察了易电离元素K、Na、Ca、Mg对铅发射强度的影响。并对微波消解葡萄酒样品的消解条件进行了考察,建立了最佳消解程序。测定铅的检出限25.18ng/mL,RSD1.5%～1.8%,线性范围0.05～100μg/mL,加标回收率99.8%～101.3%。实验结果表明,微波消解和MPTAES联用可成为测定葡萄酒中铅含量的一种操作简单、快速准确、自动化程度高,行之有效的分析方法。

Determination of Lead in Wine by Microwave Plasma Torch Atomic Emission Spectrometry

Pollution control of lead in food is very important for people health. Microwave plasma torch atomic emission spectrometry (MPT-AES) was used to determine lead in wine after digestion. Optimal conditions were chosen, such as microwave power, flow rate of carrier gas for the lead determination, flow rate of supporting gas, flow rate of oxygen shielding gas and acid concentrations. The effects of concomitant elements on determination of lead were studied. The detection limit for lead is 25.18ng/mL. The relative standard deviation for determination of wine is 1.5%～1.8%. The linear range is 0.05～100μg/mL. Standard addition recoveries are all between 99.8%～101.3%. The result shows that this determination method is effective to determine the quality of wine and it is wine and it is accurate, easy operation, high automatic and low cost.