Challenges frequently faced during the analysis of selenomethionine in complex matrices such as food and environmental samples include the lack of SI-traceable primary standards as well as difficulties associated with complex sample preparation methods resulting in potentially biased measurement results. In an effort to overcome these challenges, the National Research Council Canada has prepared two selenomethionine reference materials: a high-purity powder of natural isotopic abundance (SENS-1), and a solution of selenium-82 labelled selenomethionine (SEES-1). The purity of SENS-1, 0.961 ± 0.007 g g⁻¹ (k = 2), was established through quantitative nuclear magnetic resonance spectroscopy combined with data from inductively-coupled plasma mass spectrometry for total selenium content and the HPLC analysis of selenium-containing impurities. With the chemical purity of SENS-1 established, it was then used as the primary standard for reverse isotope dilution analysis, where the concentration of selenomethionine in SEES-1 was determined to be 1556 ± 60 μg g⁻¹ (k = 2).

中文翻译：

---

天然和82Se标记的硒代蛋氨酸参比材料的制备和认证

在食品和环境样品等复杂基质中硒代蛋氨酸的分析过程中经常面临的挑战包括缺乏可溯源的SI一级标准，以及与复杂的样品制备方法相关的困难，这可能导致测量结果出现偏差。为了克服这些挑战，加拿大国家研究委员会准备了两种硒代蛋氨酸标准物质：一种高纯度的天然同位素丰度粉末（SENS-1）和一种硒82标记的硒代蛋氨酸（SEES-1）溶液。SENS-1的纯度为0.961±0.007 gg ^-1（k= 2），是通过定量核磁共振波谱与电感耦合等离子体质谱法获得的总硒含量以及含硒杂质的HPLC分析相结合而建立的。建立了SENS-1的化学纯度后，将其用作反向同位素稀释分析的主要标准，其中SEES-1中硒代蛋氨酸的浓度确定为1556±60μgg ^-1（k = 2）。