Study On Miniaturization Of Spectrophotometer Based On CCD And Application

With the development of science and technology, small (micro) analyticalinstruments with stable performance, low cost and convenience to bring graduallyaroused people’s interest. At the same time, spectrophotometric detection at oneminiature CCD spectrometer towards commercialization, and is widely used in avariety of small spectroscopy instruments. The components of a spectrophotometer canbe roughly divided into three parts: light source system, sample loading system anddetection system. The improvement and development of these parts may enhance theperformance of current spectroscopic instruments, and even induce the innovation ofthis analytical technique. Because the traditional spectrophotometer is large in size,inconvenient to carry and requires a large sample volume, this thesis combines thelight-emitting diode (LED), microcell, optical fiber with the charge-coupled device(CCD spectrometer) and designs a small spectrophotometer which can be used forconstants and micro colorimetric determination.This dissertation describes the studies on the advances of spectral analysis in twoways:1. Based on the principle of Lambert-Beer’s law, the small spectrophotometer usesLED as light source, a homemade colorimetric device and a commercial micro cell asthe colorimetric device and a miniature CCD spectrometer as a spectrophotometricdetection system, utilizes laptop USB interface as a means to supply power and processdata, and finally comes into being using the fiber optic to all parts together. Systematicresearch on the various components of the instrument has been made and theperformance test completed proves it works well.The small spectrophotometer, which is simple in structure, low in cost andconvenient to carry and clean, can be used for constant and micro-colorimetricdetermination. The performance test results show that the small spectrophotometer is stable, precise, accurate, and can meet the actual testing requirements.2. A method for determination of trace silver with dispersed liquid-liquidmicroextraction-spectrophotometric is established, extending the scope of applicationof the small devices.The liquid-liquid microextraction is a environmentally-friendly benignsample-preparation technique, possessing obvious advantages of simplicity ofoperation, low-cost, high enrichment factor and low consumption of organic solvent.So it was widely used in the enrichment and separation of trace substance.In this work, a method for determination of trace silver with dispersedliquid-liquid microextraction-spectrophotometric is established and the optimumexperimental conditions are found to be: the wave length to be620nm,100μL ofcarbon tetrachloride as extractant,500μL of ethanol as dispersant,100μL of0.003%disulfide hydrazone as chromogenic reagent, the extraction time of3min, andcentrifuged for3min at the speed of3000r/min. The detection limit of this methodwas3.03ng/mL, linear range was0-80ng/mL and the relative standard deviation(RSD)<8.73%(n=20). Therefore, this method is10times greater in sensitivity thanthe normal method. In addition, using1mL of0.1%EDTA as a masking agent,5000times as much iron, copper, nickel, aluminum,2000times as much zinc,1000times asmuch cadmium, arsenic, manganese, cobalt,800times as much lead,600times asmuch chromium ions in the non-interfere determination, this method is easy to carryout and high in anti interference capability.