| With the development of economy, people have solved issue of food and clothing, improve the standard of living, and change dietary structure. Rich man’s diseases and geriatrics become more and more.With acceleration of the pace of life, work pressure, and sub-health population in developed area, people begin to pay attention to their health. Functional food become hailed by people. In addition,benefit of functional food is proved by strict scientific testing, functional food at home and abroad are developed under the background of it. In the body the content of iron, zinc, selenium and other trace elements is very small. But they play an important role in physiological and biochemical function of life. They are involved in human50%-70%enzyme components in body,become important carrier and electronic transfer system.They often associate with inexplicable illness.Human health is closely related with the content of trace elements in functional food.Analysis methods for the determination of trace elements in functional food are time-consuming, tedious.It is really necessary for them to be established in the preparation technology, equipment, and rapid way for the testing samples of trace elements in functional food.The purpose of this study is based on using for sample pretreatment portable microwave digestion apparatus; establishing rapid analysis technique for the determination of zinc and iron in functional food; developing the multifunctional and intelligent photochemical detector; combining with the method and photochemical detector.Through comparing rapid way for the determination of zinc and iron in functional food and analysis method of atomic absorption spectrometry, the validity of this method is confirmed.It is not only simple and fast,but also accurate and reliable.During the process of establishing the rapid method for detection of iron element in functional food, to begin with, under given coditions, Fe(Ⅲ) can react with potassium thiocyanate.They will form red complex compound, and the depth of the color is proportional to the concentration of iron ion.The best conditions of reaction were chosen by testing.Using Triton X-100as the solubilizing agent, the complex has been determined at λ1(λ=480nm) by AMMS-I detector. The linearity was shown in the range of0.0～30.0μ g/10ml for the concentration of Fe (Ⅲ).The correlation coefficient was0.9994. The detection limit was22.5μg/L. The apparent molar absorptivity was3.6×104L/(mol·cm),and relative standard deviation(RSD) was1.6%.In order to insure the reliability of the study,we do method comparison with atomic absorption spectrometry.The results show that the difference between two methods has no statistical significance.The method which has the advantages of simple operation, stable, rapid, high sensitivity, better selectivity can be used in iron-fortified food in the on-site rapid detection.During the process of establishing the rapid method for detection of zinc element in functional food, under given coditions, Zn(Ⅱ) can react with2-(5-Bromo-2-pyridylazo)-5-(di ethylamino)phenol(5-Br-PADAP).They will form red complex compound, and the depth of the color is proportional to the concentration of zinc ion.The best conditions of reaction were chosen by testing.Using Triton X-100as the solubilizing agent, The complex has been determined at λ2(λ=556nm) by AMMS-I detector. The linearity was shown in the range of0.0～12.0μg/25ml for the concentration of Zn(Ⅱ).The correlation coefficient was0.9982. The detection limit was4.5u g/L. The apparent molar absorptivity was2.3×105L/(mol·cm),and relative standard deviation (RSD) was3.7%.In order to insure the reliability of the study, we do method comparison with atomic absorption spectrometry.The results show that the difference between two methods has no statistical significance.The method which has the advantages of simple operation, stable, rapid, high sensitivity, better selectivity can be used in zinc-fortified food in the on-site rapid detection. |
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