| In the past 20th century, precious metal materials have played an important part in most aspects of the society, and they have been honored as "modern industrial vitamin". The honor is mainly because of the important effects they have brought to the environment, the energy and the science that human beings rely on, However, as the research on precious metals moves on, elements such as Au, Ag and Pd are found to do harm to the human body if their contents are over amounted. Along with this, with the development of industry and the wide use of the precious metals, the pollutions they have brought to the environment cannot be overlooked. Beryllium is a harmful element, our nation has laid down hygienic standard for Be in drinking water, it is still not known about the hygienic standard for its content in human body. In order to research the background value of the four elements which accumulate in human body, we have respectively set up new graphite furnace atomic absorption systems to conduct detecting research on their contents in biological samples and chemical reagents. Metals' background value in human bodies reflects the extent that they have produced the environmental pollution. This research is also helpful in providing evidence for the environmental pollutions produced by these metal elements and also helpful in removing the environmental pollution.The content of this paper is as follows:1. A method was established for the determination of gold in human hair by GFAAS.In the presence of extractant acetic ester, the matrix interference was eliminated efficiently and when the graphite tube was coated with Yttrium the sensitivity was improved .The method could be used for the determination of trace gold in biological samples or ore samples. The detection limit is 2.4×10-11g, and the relative standard deviation is 3.3%.2. Different kinds of extractants and matrix modifiers have been tested for the determination of trace silver in human hair by GFAAS. A simple method was developed after preconcentration with methyl isobutylketone, KI and EDTA were added in the sample solution as complex agent and matrix modifier, the optimized content of KI and EDTA in sample solution were 0.8%. The matrix interference of elements which were common inbiological samples was eliminated efficiently, additionally, the recovery of this method is much better. Calibration curves for silver were linear across the rang of 0~25ng/mL. The relative standard deviation is 3.3%, and the detection limit is 1.0× 10-10g.3. Different kinds of coating layers and matrix modifiers have been tested for the determination of trace beryllium in biological samples by GFAAS. A new method using molybdenum coated graphite tube with lithium nitrate as matrix modifier was established.The result shows that ashing temperature increased while atomization temperature decreased. Meanwhile the method has strong ability to resist interference,This method has been used for the determination of trace beryllium in standard reference soil sample and human hair. The detection limit is 1.4× 10-11g, and the relative standard deviation is 4.8%.4. A new method for the determination of trace palladium in 1-deoxynojirimycin synthesized by new means. The graphite tube coated with molybdenum and the matrix modifier of lithium nitrate were used in this method, then, the matrix interference was eliminated efficiently in determining actual samples. The calibration curve is linear over the range of 0~50 ng/g with detection limit of 3.5 × 10-11g and RSD of 4.7%. |
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