Michalke B, Schramel P
GSF Research Centre for Environment and Health GmbH, Oberschleissheim, Germany.
Biol Trace Elem Res. 1997 Winter;59(1-3):45-56. doi: 10.1007/BF02783229.
Selenium- (SE) organo compounds of pooled human milk (7th-14th d after delivery) were separated by centrifugation and subsequent size-exclusion chromatography (SEC) as described in ref. (1). The SEC fractions were used for Se determinations by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) in parallel to identification procedures of the organic ligands by two different capillary zone electrophoresis (CZE) methods. Further, the combination of isotachophoresis- (ITP) CZE with ETV-ICP-MS was used for final identifications. Mass balances were carried out at each analytical step for quality assurance. Reinjection experiments were performed to check the stability of Se-organo compounds during the analytical procedure. These quality-control experiments showed that no species transformations took place during the analytical procedure, and the Se species were native in human milk. The identification and quantification of organic ligands were clear and resulted in values of 2 (+/- 0.2) mg/L GSH/GSeH, 2 (+/- 0.22) mg/L cystamine/Se-cystamine, 4 (+/- 0.4) mg/L cystine/ Se-cystine, and 1 (+/- 0.18) mg/L methionine/Se-methionine. Unfortunately, a differentiation between sulfur (S) and Se analogs was not possible with the applied CE methods. The Se values per organic ligand were determined as 2.5 (+/- 0.23) mg/L associated with GSH (as GSeH), 3.1 (+/- 0.31) mg/L associated with cystamine (as Se-cystamine), 5.2 (+/- 0.4) mg/L associated with cystine (as Se-cystine), and 1 (+/- 0.1) mg/L associated with methionine (as Se-methionine).
将产后第7至14天收集的人乳中的硒（SE）有机化合物通过离心及随后的尺寸排阻色谱法（SEC）进行分离，如参考文献（1）所述。SEC馏分用于通过电热蒸发电感耦合等离子体质谱法（ETV-ICP-MS）测定硒，同时通过两种不同的毛细管区带电泳（CZE）方法对有机配体进行鉴定。此外，等速电泳-（ITP）CZE与ETV-ICP-MS联用进行最终鉴定。在每个分析步骤进行质量平衡以确保质量。进行再注入实验以检查分析过程中硒有机化合物的稳定性。这些质量控制实验表明，分析过程中没有发生物种转化，人乳中的硒物种是天然存在的。有机配体的鉴定和定量清晰明确，结果为谷胱甘肽/硒代谷胱甘肽（GSH/GSeH）为2（±0.2）mg/L、胱胺/硒代胱胺为2（±0.22）mg/L、胱氨酸/硒代胱氨酸为4（±0.4）mg/L、蛋氨酸/硒代蛋氨酸为1（±0.18）mg/L。遗憾的是，所应用的CE方法无法区分硫（S）和硒类似物。每个有机配体的硒含量分别确定为与谷胱甘肽（以GSeH形式）相关的2.5（±0.23）mg/L、与胱胺（以硒代胱胺形式）相关的3.1（±0.31）mg/L、与胱氨酸（以硒代胱氨酸形式）相关的5.2（±0.4）mg/L、与蛋氨酸（以硒代蛋氨酸形式）相关的1（±0.1）mg/L。
