Study On The Coupled Technique Of Atomic Absorption Spectrometry And Its Application

As one of effective detections of the trace and ultratrace element, atomic absorption spectrometry offers extending good advantages in terms of simple structure, easy operation, cheap equipment, low cost, good selectivity and good precision, so it is widely used in the field of metallurgical, geological, chemical, medical, clinic investigation and food hygiene.Hydride generation-atomic absorption spectrometry (HG-AAS) enhanced detection power of AAS to hydride-forming elements. The detection limits of hydride-forming elements can be improved by one or two orders of magnitude, and nearly eliminated matrix spectrum interference. Therefore, it provided a new way to solve complex matrix interference and speciation analysis . The high-efficient capillary electrophoresis (CE) was developed rapidly in the eighties of the 20th century as a novel separation and analysis technology. It was considered to be one of the strongest influence branches of analysis field at the end of last century, as well as the frontier of this field. It has many advantages: high efficiency, quick analysis speed, many analysis modes, little reagent consumption, wide application, easy automation, etc. Thus it shows extremely important application to life sciences, biotechnology, clinical medicine, medicine analysis and environmental science and so on. It's become very impressive in the field of speciation analysis. In 21st century, elements speciation analysis is one of the important area in modern analysis science. The researchers faced severe challenges. A sigle atomic absorption spectrometry can not provide the imformations of elements speciation. Acorrding to the characteristics of speciation analysis and complexity of the sample, it requires the chemical detection equipment combined with isolation technology. In order to improve speciation analysis power of atomic absorption spectrometry, we combined capillary electrophoresis and hydride generation with atomic absorption spectrometry to realized the combination of efficient separation and element alternative determination.In this paper, the research has been carried on foundation of coupling capillary electrophoresis with hydride generation and atomic absorption spectrometry and its application to the speciation analysis. The main contents and results were shown as follows: 1. A novel interface of capillary electrophoresis hydride generation with electrothermal quartz tube atomic absorption spectrometry (CE-HG-EQT-AAS) was developed. The interface had the advantages of simple structure, easy operation good stability, less dead volume, good conductivity and good gas-liquid separation efficiency. The analysis performance of the interface has been studied, such as eletrophoresis voltage, the inner diameter of quartz tube, the carrier gas flow rate, the acidity of HCl, and the NaBH4 concentration. The application of the developed CE-HG-EQT-AAS to the speciation analysis of Hg2+ and CH3Hg+ was highlighted. Detection limits of these species were 0.38μg/ mL and 0.45μg/ mL, reapectively. RSD for those was lower than 2 %.2. Speciation analysis of mercury in goldfish tissue was studied using capillary electrophoresis hydride generation with electrothermal quartz tube atomic absorption spectrometry. The methylmercury in poisning goldfish muscle had been analysed according to peak height. After 15 days, the content of methylmercury in dry goldfish muscle was 8.17μg·g-1.3. An ingenious interface for CE-HG-GFAAS had been designed. The interface had the advantages of good stability, simple stucture and easy control. The effects of current of hollow cathode lamp, atomizing temperature, the carrier gas flow rate, acidity of HCl and the NaBH4 concentration on As signal intensity were discussed. The application of the developed CE-HG-GFAAS to speciation analysis of arsenic was highlighted. Detection limits of As(III) and As(V) were 0.39μg/ mL and 0.48μg/ mL, respectively. RSD for those was lower than 5.1 %.