建立利用超滤-原子吸收技术分析保健品中金属元素形态的方法。通过0.45 μm微孔滤膜实现样品中可溶态和悬浮态的分离，选择D101大孔树脂分离可溶态中有机态和无机态，再利用超滤技术以膜的截留分子质量分离有机态。使用微波消解-高分辨-连续光源火焰原子吸收光谱法测定不同形态的Ca、Fe和Zn，结果表明3种保健品中Ca、Fe和Zn含量都很丰富，主要以可溶态形式存在，可溶态中以有机态为主。锌铁钙口服溶液中有机态Ca主要分布在分子量<300 ku的分子中，有机态Fe和Zn主要分布在分子量<8 ku的分子中；黄精酵素口服液中有机态Ca和Fe主要分布在分子量<300 ku的分子中，有机态Zn主要分布在分子量<8 ku的分子中；固体酵素中有机态Ca、Fe和Zn主要分布在分子量<300 ku的分子中。该方法具有较高的实用价值，为进一步研究保健品的功能，特别是有益金属元素的生物有效性提供基础数据。

Amethod was developed for the speciation analysis of metal elements in health-care food by ultrafiltration-atomic absorption spectrophotometry. The suspended and soluble metal elements in health-care food were obtained by 0.45 μm filtration membranes, and the inorganic and organic metal elements in soluble species were separated by D101 macroporous resin. Moreover, the organic-form metal elements were separated based on the molecular weight with ultrafiltration membranes. The content of calcium, iron and zinc in different species were determined by microwave digestion-high resolution-continuum source flame atomic absorption spectrometry. The results showed that the three kinds of health-care food were all rich in calcium, iron, and zinc. Most of them were in soluble form, of which the organic forms were more than half. The organic calcium of oral liquid including calcium, iron and zinc was mainly distributed in the fraction with molecular weight< 300 ku, while the organic iron and zinc were mainly distributed in the fraction with molecular weight< 8 ku. Most of the organic-form calcium and iron of oral liquid including polygonatum and enzymes were distributed in the molecular weight<300 ku fraction, while the organic zinc was mainly distributed in the molecular weight < 8 ku . All the organic form of them in solid including enzyme were mainly distributed in the molecular weight <300 ku fraction. Therefore, the proposed method has favorable practical value. It provides much basic data for the further study on the functions of the health-care food, especially for the biological effectiveness research of beneficial metals.

江苏省前瞻性联合研究项目（BY2015024-04）；江苏省苏北科技专项（BN2015012、BN2106017）；国家星火计划项目（2013GA690417）；国家自然科学基金面上项目（31270577）