Suzuki K T, Sasakura C, Ohmichi M
Faculty of Pharmaceutical Sciences, Chiba University, Japan.
J Trace Elem Med Biol. 1997 Jun;11(2):71-6. doi: 10.1016/S0946-672X(97)80029-6.
Cadmium (Cd) in polished rice grains was extracted under various conditions and the chemical forms of the metal in soluble fractions were determined together with copper, zinc and other metals by HPLC with on-line detection by inductively coupled argon plasma (ICP)--mass spectrometry (MS). Cd (753 ng/g) in rice grains grown in Cd-contaminated rice fields was mostly bound to glutelin in soluble fractions. Binding of Cd in vitro to constituents in rice grains was examined by incubating CdCl2 enriched with 113Cd (96.3% enrichment) in a suspension of powdered rice grains. Distributions of exogenous 113Cd in the soluble fraction of Cd-contaminated rice grains was identical with that of endogenous Cd on a size-exclusion column, and the metal was shown to bind to glutelin up to 5.0 micrograms/g in the control rice grains, indicating that exogenous Cd can be bound to glutelin up to this capacity. Simultaneous speciation of exogenous 113Cd and endogenous 111Cd was demonstrated to be highly effective for comparing the binding of Cd natural and artificial origins.
在不同条件下提取精米中的镉（Cd），并通过高效液相色谱法（HPLC）结合电感耦合氩等离子体质谱（ICP）-质谱（MS）在线检测，测定可溶部分中该金属与铜、锌及其他金属的化学形态。在受镉污染稻田中种植的稻米含镉量为753纳克/克，其可溶部分中的镉大多与谷蛋白结合。通过在米粉悬浮液中孵育富含113Cd（富集度96.3%）的CdCl2，研究了镉在体外与稻米成分的结合情况。在尺寸排阻柱上，镉污染稻米可溶部分中外源113Cd的分布与内源镉相同，且在对照稻米中该金属与谷蛋白的结合量可达5.0微克/克，表明外源镉可与谷蛋白结合至该容量。结果表明，同时对外源113Cd和内源111Cd进行形态分析对于比较天然来源和人工来源镉的结合情况非常有效。
