毛细管电泳-电感耦合等离子体质谱联用测定海藻中铅形态化合物

建立了毛细管电泳( CE)与电感耦合等离子体质谱( ICP-MS)联用技术测定铅离子( PbⅡ)、三甲基铅(TML)和三乙基铅(TEL)3种不同形态铅化合物的方法,以及海藻中不同形态铅化合物的提取技术,实现了海藻中3种铅形态化合物的定性定量分析。结果表明：以70 mmol/L H3BO3-17.5 mmol/L Na2B4O7(pH 8.90)为缓冲溶液,在最佳CE-ICP-MS条件下3种铅化合物20 min内可实现有效分离,重现性较好,迁移时间RSD﹤4%,峰面积的RSD﹤5%；在10~200μg/L 范围内3种铅化合物线性较好,相关系数大于0.90； PbⅡ、TML和TEL的CE-ICP-MS检出限(3S/N,以Pb计)分别为0.091,0.023和0.030μg/L；采用分步提取海藻中Pb元素,提取率高达80%以上,以藻体为基底 PbⅡ, TML 和 TEL 回收率分别为103.6%,95.7%和90.6%；通过检测紫菜和海带中铅含量,结果显示藻体内Pb主要以PbⅡ形式存在。本方法具有简单、高效、样品消耗量少等优点,可为海藻及其它海产品的质量控制提供技术支撑。

Determination of Lead Species in Algae by Capillary Electrophoresis-Inductively Coupled Plasma-Mass Spectrometry

A method of capillary electrophoresis ( CE ) combined with inductively coupled plasma-mass spectrometry ( ICP-MS) was established for the determination of lead ion ( PbⅡ) , trimethyl lead ( TML) and triethyl lead ( TEL) . Meanwhile, the extraction technology of different species of lead in algae was established and optimized for the qualitative and quantitative analysis. The results showed that three kinds of lead compounds could be effectively separated within 20 min by CE-ICP-MS with 70 mmol/L H3 BO3-17. 5 mmol/L Na2B4O7(pH 8. 90) as a buffer solution. There was a good reproducibility of migration time (RSD﹤4%) and peak area ( RSD﹤5%) . Three kinds of lead compounds had good linear relationship within 10-200μg/L with the correlation coefficient larger than 0. 90. The detection limits of PbⅡ, TML and TEL (S/N=3, Pb) were 0. 091, 0. 023 and 0. 030 μg/L, respectively. The extraction rate of Pb reached more than 80% by using fractional extraction, and the recovery rates of Pb Ⅱ, TML and TEL were 103. 6%, 95. 7% and 90. 6%, respectively, with algae as the substrate. The lead content detection of laver and kelp showed that Pb in algae mainly existed in the form of Pb Ⅱ. The method had the advantages of siplicity, high efficiency and low sample consumption, which could provide technical support for the quality control of marine algae and other marine products.