用三元络合物萃取-火焰原子吸收法测定食品中痕量镉  

DETERMINATION OF TRACE CADMIUM IN FOOD SAMPLES BY TRIPLE COMPLEX EXTRACTION AND FLAME ATOMIC ABSORPTION SPECTROMETRY

作　　者：韩华云[1] 王亚鸽[1] 杨琳[1] 张威[1] 贾春玲[1] 夏辉[1] 

机构地区：[1]郑州大学化学系,河南郑州450052

出　　处：《河南工业大学学报（自然科学版）》2011年第6期67-71,共5页Journal of Henan University of Technology：Natural Science Edition

摘　　要：建立了一种测定食品中痕量镉的新方法.以茜素黄R和邻菲罗啉为螯合剂,以甲基异丁基甲酮为萃取剂,直接以有机相进样测定,提高了测定的选择性和灵敏度.考察了介质酸度、缓冲溶液及螯合剂的用量等对测定的影响,优化了测定条件.详细研究了常见元素对镉元素测定的干扰情况,用酒石酸钾钠做掩蔽剂,可以消除大量共存组分的影响.在最佳工作条件下,镉离子质量浓度在3.0×10-3～0.25μg.mL-1范围内线性关系良好,方法的检出限为1.7×10-3μg.mL-1,对0.2μg.mL-1的镉标准溶液进行9次平行测定,相对标准偏差为1.1%,检出限低,重现性好.该法用于食品中镉的测定,结果满意.In this study, a new analytical method was developed for determination of trace cadmium in food by flame atomic absorption spectrometry. In the proposed method, 1,10-phenanthroline monohydrate and alizarin yellow R were used as chelating agents, and methyl isobutyl ketone （MIBK） was selected as extractant. The samples were injected in flame atomic absorption spectrometry in form of organic phase, and the selectivity and the sensitivity of the determination of cadmium were greatly improved. The effects of pH, concentration of buffer solution and chelating agent on liquid-liquid extraction were studied, and the determination conditions were optimized. The interference of common coexistent elements on the determination of cadmium was studied in detail, and the effects of the coexistent elements could be eliminated by using potassium sodium tartrate. Under the optimized conditions, the calibration graph had good linearity in the range of cadmium mass concentration of 3.0 x 10-3 to 0.25 ixg.mL-1 and the detection limit was 1.7 ~ 10.3 ~g.mL1. The relative standard deviation was 1.1% after carrying out nine parallel determination of a 0.2 txg ＂mLt cadmium standard solution. This analytical method could be applied for the determination of cadmium in food samples with low determination limit, good repeatability and satisfactory results.

关 键 词：三元络合物 原子吸收光谱法 食品 痕量 镉 

分 类 号：TS207.3[轻工技术与工程—食品科学]