微波消解-溶出伏安法对食品中铜、铅、镉的同时测定

Determination of Copper,Lead and Cadmium in Food by Microwave Digestion-Anodic Stripping Voltammetry

采用微波消解结合同位镀汞阳极溶出伏安法对茶叶、紫菜和西洋菜等食品中的铜、铅、镉进行了测定，并优化了微波消解、电解缓冲液、富集电位等实验条件。采用标准加入法定量，cu、Pb、cd的线性范围分别为0．040—1．768、0．080～1．768、0．040～1．768mg／L，相关系数分别为0．9984、0．9982、0．9970，检出限分别为0．008、0．016、0．008mg／L，相对标准偏差（n=5）分别为4．1％、0．92％、2．0％。该方法测定茶叶、紫菜、西洋菜等实际样品的铜、铅、镉含量，加标回收率分别为98％－109％、94％～103％、100％－112％；将测定结果与原子吸收光谱法检测结果对比，表明此方法简便、快速，且具有较高的灵敏度、较好的选择性和可靠性。

A method for the determination of Cd, Pb, Cu in food by mircrowave digestion （MWD） method as pretreatment procedures combined with anodic stripping vohammetry （ASV） using a rotating glassy carbon/mercury film electrode was proposed. A series of experimental conditions, such as the pressure and temperature of microwave digestion, pH of the buffer solution and deposition potential, were optimized. Under the optimal conditions, the linear ranges of Cu, Pb and Cd were 0. 040 - 1. 768, 0. 080 - 1. 768 and 0. 040 - 1. 768 mg/L, respectively. The limits of detection （LODs） of Cu, Pb and Cd were 0. 998 4, 0. 998 2 and 0. 997 0, respectively and RSD of repeatabilities were 4. 1% , 0.92% , 2.0% , respectively. The spiked recoveries of Cu, Pb and Cd were in the range of 98%- 109% , 94%- 103% , 100%- 112% , respectively. The method showed good sensitivity and repeatibility, and was applied in the determination of Cu, Pb and Cd in real sample. The results were in good agreement with those obtained from the atomic emission spectrometry（AAS） method.