Brätter P, Blasco I N, Negretti de Brätter V E, Raab A
Hahn-Meitner Institute Berlin, Department of Trace Elements in Health and Nutrition, Germany.
Analyst. 1998 May;123(5):821-6. doi: 10.1039/a801284i.
The aim of this work was twofold: to study the binding pattern of trace elements in formulas as compared with breast milk and the relationship between trace elements in breast milk and in maternal dietary intake. To investigate the binding form of trace elements in these nutritive fluids, methods for protein separation were combined with methods for trace element determination in the eluted fractions. HPLC and ICP-AES or ICP-MS were coupled on-line for the simultaneous speciation of elements of nutritional interest, viz., Ca, K, Mg, P, S, Co, Cu, Fe, I, Mn, Mo, Se and Zn, and also the heavy metals Cd and Pb in both human mild whey and formulas. In order to minimize interactions between the labile metal protein complexes and the column material, size-exclusion chromatography was used for protein separation. The binding pattern of trace elements in formulas is significantly different from that in breast milk and depends on its main component (cow's milk or soy), its processing (hydrolysis) and the chemical form (inorganic) of the added compounds. For example, compared with breast-fed infants the iron supply of formula-fed infants is much higher (up to 20-fold); in addition, the binding forms of Fe are very different in the two fluids. This has to be evaluated with respect to interactions with other elements during intestinal uptake. The investigation of breast milk samples from different regions of the world showed comparable shapes for teh elution profiles and for Mo and Se a dependence on the regional maternal dietary intake. Speciation studies carried out on breast milk samples as a function of the selenium content showed significant changes in the zinc-binding pattern. In particular, citrate (as a zinc-binding component) was found to decrease with increasing dietary selenium intake of the mother.
研究配方奶粉中微量元素的结合模式，并与母乳进行比较，以及研究母乳中微量元素与母亲膳食摄入量之间的关系。为了研究这些营养流体中微量元素的结合形式，将蛋白质分离方法与洗脱组分中微量元素的测定方法相结合。高效液相色谱法（HPLC）与电感耦合等离子体发射光谱法（ICP - AES）或电感耦合等离子体质谱法（ICP - MS）在线联用，用于同时分析具有营养意义的元素，即钙（Ca）、钾（K）、镁（Mg）、磷（P）、硫（S）、钴（Co）、铜（Cu）、铁（Fe）、碘（I）、锰（Mn）、钼（Mo）、硒（Se）和锌（Zn），以及人初乳清和配方奶粉中的重金属镉（Cd）和铅（Pb）。为了尽量减少不稳定金属蛋白复合物与柱材料之间的相互作用，采用尺寸排阻色谱法进行蛋白质分离。配方奶粉中微量元素的结合模式与母乳中的显著不同，这取决于其主要成分（牛奶或大豆）、加工方式（水解）以及添加化合物的化学形式（无机）。例如，与母乳喂养的婴儿相比，配方奶粉喂养的婴儿铁供应量要高得多（高达20倍）；此外，两种流体中铁的结合形式非常不同。这必须在肠道吸收过程中与其他元素的相互作用方面进行评估。对来自世界不同地区的母乳样本进行的调查显示，洗脱曲线形状具有可比性；对于钼和硒，其含量取决于地区母亲的膳食摄入量。对母乳样本进行的随硒含量变化的形态分析研究表明，锌结合模式发生了显著变化。特别是，发现柠檬酸盐（作为锌结合成分）会随着母亲膳食硒摄入量的增加而减少。
