Abstract: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.
