Research On Accmulation Characteristics Of Trace Zinc In Bean Sprout

Zinc is one of the essential trace element and it plays an important role in maintaining the normal physiological function of human.This paper reviewed about the existing forms of zinc, biological function of zinc, absorption of zinc and research status on the zinc-rich food, as well as the methods of detection of zinc. The new method for the rapid detection of zinc was established by using bismuth film modified glassy carbon electrode as working electrode, combined with differential pulse stripping voltammetry and ultrasonic techniques. On the orther hand, zinc-rich bean sprout was prepared by zinc bioaccumulation on mung bean in the process of germination. The main work of this thesis is as follows:â‘ Trace zinc in bean sprout was determined by sono-differential pulse stripping voltammetry on a synchronously plated bismuth film electrode. Under the optimized experimental conditions, the characteristic peak of Zn²⁺ was got at -1.14V(vs.SCE). The linear range for detection was 10～400μg/L and equation was expressed as I=0.0576C+1.1113, r=0.9986, the detection limit was 0.8μg/L, and RSD was 3.17% through 10 parallel determinations. Comparing to the traditional different pulse voltammetry, stripping peak current of Zn²⁺ was increased near to one order of magnitude and the sensitivity was improved by the sono-voltammetry. This method could be used to detect Zn in tap water?and bean sprout samples with good results,which were quite corresponding to the value obtained by atomic absorption spectrometry.â‘¡The optimal culture condition was obtained by the study on the growth of bean sprout, the absorption and accumulation of zinc, organic zinc transformation and the effect on SOD enzyme activity. Considering about the above factors and the recommended daily intake of zinc (2.2mg), the optimum concentration of zinc culture medium was gained 75mg/L finally.The establishment of a new detection method of zinc and the research on the absorption and accumulation of zinc on bean sprout provided a certain reference value for the application of electrochemical technique to the detection of trace element and effective method of zinc supplement.