Study Of Microfluidic Chips With Atomic Fluorescence Spectrometry

The area of micro total analysis systems (μTAS) is a rapidly developing field for biochemistry analysis, chemistry analysis and pharmaceutical analysis. Microfluidic chip is one of the main parts of uTAS. Microfluidic chip based analysis has merits of little volume, low consumption and high analysis throughput. It has been combined with many analysis techniques, such as capillary electrophoresis. Atomic fluorescence spectrometry, which has the advantages of high sensitivity and low detection limits, has been widely applied in the measurements of heavy metal in environment, food and petrochemicals. In this work, a novel microfluidic chip system coupled with atomic fluorescence spectrometric system was developed and applied in determination of mercury. This system has the merits of little sample and reagent consumption and low cost.In the first chapter, we introduced the principle of atomic fluorescence spectrometry and its application. The principle of cold vapor generation-atomic fluorescence spectrometry was also described.In the second chapter, various routine and miniaturized gas-liquid separation techniques were reviewed.In the third chapter, a novel microfluidic chip system combined with atomic fluorescence spectrometry system was developed and applied in measurement of mercury. The mercury sample and reagent delivered by a syringe pump were mixed and reacted in the microchannel, mercury vapor generated in the reaction was separated in the gas-liquid separation device in the chip based on capillary effect. The mercury vapor was detected by a lab-made atomic fluorescence spectrometric detector. The operation conditions of the present system were optimized, including flow rate, reaction time and reagent concentration. The performance of the present system was demonstrated in the measurement of mercury with a linear range of 0.05 -1 mg/L. The regression equation is y= 9.4662x+2.5702,R~2=0.9888. The repeatability for 1 mg/L Hg solution was 6.6% (RSD, n=5). The detection limit for mercury was 11 μg/L.