Study On The Coupled Technique Of Atomic Fluorescence Spectrometry Determination Of Heavy Metals In Environmental Sample

Speciation of elements in natural samples, was one of thepredominant development trends of modern analysis science. Highperformance liquid chromatography associated with atomic fluorescencewas an important technology for speciation analysis, had beensuccessfully applied to analysis a variety of elements’ species inenvironmental samples. A literature survey revealed that there werevarious forms of selenium in aquatic products, the bioavailability ofselenium is closely interlinked with their chemical speciation, but fewrelated researches had been reported in China. Therefore, developed aspeciation method analysis combining atomic fluorescence spectrometerwith high performance liquid chromatography to detect the species of Sein aquatic products is indeed. This practice could vigorously promote theenvironmental protection supervision departments to develop deep-leveldetection for selenium, on the other hand, it was an important promotionfor developing atomic fluorescence spectrometer. Then a new and sampletechnique for the simultaneous determination of trace arsenic, mercury,selenium and lead in biologic samples by hydride generation-atomicfluorescence spectrometry was developed，the purpose of this practice isto further understand the extent of heavy metal pollution in aquaticproducts. In order to prove Atomic Fluorescence Spectrometry was anadvanced method to analysis heavy metals, the comparison ofabove-mentioned two analytical instruments for analyzing was studied.The main results in this thesis were as follow:Base on the studying of atomic fluorescence spectrometer andcoupling with high performance liquid chromatography as the separation means, the working conditions of the instrument, carrier concentration,reducing agent concentration, the selection of high performance liquidchromatography mobile phase, flow rate of HPLC mobile phase wereoptimized in detail. Under the optimized experiment conditions, theSeCys, SeMet and Se(IV)’s fluorescence signal and the density becamethe linear relationship in0~80μg/L, the linear correlation coefficient were0.9992,0.9998,0.9991,separately.Detection limit of organic and inorganicSelenium were SeCys1.66μg/L, SeMet0.91μg/L, Se(IV)1.10μg/L,respectively, the relative standard deviations (n=11) for the seleniumspecies were1.15%,0.41%and0.33%, separately. And determined theselenium species in the aquatic samples with the establishment method,the recovery were range from87.3%to102.6%. The high sensitivity, lesscomplex and repeatability of this method can meet the requirements ofthe speciation analysis for aquatic samples.Determining of trace arsenic, mercury, selenium and lead in biologicsamples using Microwave Digestion-Hydride Generation-AtomicFluorescence Spectrometry was established. The composition of digestionmethod and operational conditions of HG-AFS were studiedsystematically. Under optimal experimental conditions, the proposedmethod was provided with linear correlation all above0.9990, and thedetection limits of0.0326,0.0093,0.0814and0.0792μg/L were obtainedfor As, Hg, Se and Pb, respectively. The recoveries of spiked sampleswere of the range89.2~101.8%and precision was fine RSD<5%.Theresults showed close agreement with the reference values in two standardreference materials of GB2762and GB18406, but only Arsenic content ofsome products exceeded the national standards. This study had importantsignificance and relevance of the corresponding content of heavy metalsin aquatic products for environmental water.Developing a comparison study between hydride generation-atomicfluorescence spectrometry and atomic absorption spectrometry foranalyzing heavy metal element in aquatic products, our study intended toexplain their relationship and characteristics, and provided evidence formeasurement result explaining and implication. The results showed thatthere was little difference between the two detection methods. Thehydride generation atomic fluorescence spectrometry got lower detection limit, higher sensitivity, better accuracy, this method was more suitablefor the analysis of trace heavy metals in aquatic products.