Design Of Vitamin A Fluorescerence Detection System

Vitamin A is a sort of organic compound witch is necessary for maintaining normal physiological functions, including keeping dark vision and epithelium healthy, preserving immunity system's ability, and also promoting growth. Deficient of vitamin A for a long time may induce an avitaminosis A, and suffer diseases such as nyctalopia and xeroma. As can be deposited in the liver and fat, assimilating superabundant vitamin A may also result in hypervitaminosis A.Detecting the content of body vitamin A is significant, especially for the infants and pregnant women, which can be used as an important reference in estimating health conditions. In the developing countries like in the Africa and Southeast Asia infants deficient of vitamin A is serious, there is the same problem in the depressed areas in China as well. So popularizing vitamin A detecting is helpful to improving population health levell.This paper mainly discusses several contents hereinafter:â’ˆAccording to the fluorescence characteristic of vitamin A, a fluorescent detecting method is founded, which uses 345nm excitation light irradiating vitamin A's organic solution and measuring fluorescence intensity at 490nm.â’‰Based on the vitamin A's detecting method motioned above, an optical system for fluorescence detecting is designed. The system contains excitation light source, 345nm and 490nm filter slices, Y branched fiber and photo detector using a photomultiplier tube.â’ŠSystem uses a standard 96 tiny hole board, a mechanism scanning frame is designed. Using two phase hybrid step motor under open loop control can accomplish precision scanning.â’‹Uses PIC16F877A microcontroller as the core of the circuit, and introduces the soft ware programming briefly.Designing the system aims at exerting the advantages of fluorescent analyses, like high sensitivities and high characteristic, and making up a stable simple accurate vitamin A fluorescence detecting system meeting practical needs.