| Summary: | 碩士 === 國立中山大學 === 化學系研究所 === 101 === The majority of analysis by ICP-MS are carried out on solutions using a conventional pneumatic nebulizer. However, the type of analytical tasks that can be solved by ICP-MS can be extended using a number of other sample introduction techniques that can be easily adapted to ICP-MS. Electrothermal vaporization (ETV) is one of the sample introduction techniques, that is currently employed in ICP-MS. This alternative technique to solution nebulization presents several advantages, including improved sensitivity, small sample size requirements and the capability of solid analysis. Perhaps the most notable benefit of ETV-ICP-MS is the possibility of performing direct solids analysis.
Ultrasonic slurry sampling is one of the methods for direct solid sample introduction, that has been successfully used in ETAAS. More recently, this approach has been extended to ETV-ICP-MS. Compared to traditional sample preparation methods such as acid digestion and dry pyrolysis, slurry sampling offers several benefits including reduced sample preparation time, reduced possibility of sample contamination, and decreased possibility of analyte loss before analysis. Furthermore, slurry sampling combines the benefits of solid and liquid sampling and permits the use of conventional liquid sample handling apparatus such as an autosampler.
First reaserch, ultrasonic slurry sampling electrothermal vaporization isotope dilution inductively coupled plasma mass spectrometry USS-ETV-ICP-MS. has been applied to the determination of Nd, Gd, Dy and Lu in seaweed samples. Thioacetamide (TAC) and 8-hydroxyquinoline-5-sulfonic acid (8-HQ-5-SA) was used as the modifier. Since the sensitivities of the elements studied in seaweed slurry and aqueous solution were quite different, standard addition method was used for the determination of Nd, Gd, Dy and Lu in these seaweed samples. This method has been applied to the determination of Nd, Gd, Dy and Lu in NIST SRM 1547 peach leaves reference material and four seaweed samples. Analysis results of reference sample NIST SRM 1547 peach leaves agreed satisfactorily with the information values. Detection limits estimated from standard addition curves were 0.3, 0.6, 0.02 and 0.02 ng g-1 for Nd, Gd, Dy and Lu, respectively.
Second research, a low temperature electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) method was developed for the determination of the medicinal activated charcoal, using Ethylenediaminetetraacetic acid (EDTA) as chemical modifier. In this study, a relatively low vaporization temperature was used which separated the analyte from the major matrix components and improved the ion signals significantly. Since the sensitivities of Cd, Sb, Te, Hg, Tl and Pb in various medicinal activated charcoal slurries and aqueous solution were quite different, the standard addition method and isotope dilution method were used for the determination of Cd, Sb, Te, Hg, Tl and Pb in these medicinal activated charcoal samples. This method has been applied to the determination of Cd, Sb, Te, Hg, Tl and Pb in NIST SRM 1633b coal fly ash reference material and four seaweed samples. Analysis results of reference sample NIST SRM 1633b coal fly ash agreed satisfactorily with the certified values. Detection limits estimated from standard addition curves were 0.2, 0.1, 0.1, 0.1, 0.02 and 0.6 ng g-1 for Cd, Sb, Te, Hg, Tl and Pb, respectively.
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