用同位素稀释法测定牛肝和人血清中的锌和硒

结合阴离子交换树脂分离及巯基棉分离技术，采用同位素稀释-电感耦合等离子体质谱法测量了国际比对样品CCQM-K49牛肝样品和人血清样品中的锌和硒。结果表明，对于待测元素含量较高的样品，不经分离，高倍稀释可有效减少基体的干扰；而对待测元素含量较低的样品，则必须经过分离才能准确测量。CCQM-K49牛肝样品中锌和硒的质量分数分别为(179.8±1.2)×10^-6和(2.067±0.027)×10^-6，BW3215人血清标准物质中锌的质量分数为(1.164±0.024)×10^-6，国际比对IMEP-17人血清样品中硒的质量分数(0.0780±0.0014)×10^-6，测量结果均与比对的中心值接近，符合检测的要求。

Determination of zinc and selenium in bovine liver and human serum samples by isotope dilution

Zinc and selenium in bovine liver (international standard sample CCQM-K49) and human serum have been determined by isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) combined with separation by means of an anion exchange resin and cotton impregnated with thioglycollic acid. It was shown that matrix interference can be significantly reduced by diluting the sample many times, but elements present at low levels in the sample must be purified for precise determination. In the CCQM-49 bovine liver sample, the measured mass ratios of zinc and selenium were (179.8±1.2)×10^-6 and (2.067±0.027)×10^-6, respectively. The mass ratio of zinc in the human serum reference material (BW3215) was found to be (1.164±0.024)×10^-6 and the mass ratio of selenium in IMEP-17 serum was (0.0780±0.0014)×10^-6. The results showed good reproducibility. 