| Summary: | 博士 === 國立清華大學 === 化學系 === 97 === Laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) is capable of direct analysis, bulk analysis, multi-elemental analysis, isotopic analysis, micro analysis, and spatially analysis. Therefore, applications of LA-ICPMS now span a great range of academic and industrial fields that include geological, archaeological, forensic, biological and material research. However, for quantification analysis, calibration remains a challenge for analysis of a wide variety of samples. In addition, upgrading the instrumentation, analyst should pay more attention to find the cooperation of different scientific field
There are two topics included in this work. Firstly, the aim of the present study was to utilize LA-ICPMS to establish a high spatially-resolved single hair analysis, including elemental retrospect analysis and cross-sectional analysis. Hair, one of the metabolic end products, can continuously record the physical status among its lifecycle. In particularly, metals can accumulated into the hair structure along a single strand during growth. In this study, a thallium-poisoned hair was investigated. The time resolution of the retrospect analysis can be down to one day. In this study, we established a ease and rapid cross-section elemental analysis method by utilizing the capability of depth profile and micro trace analysis of LA-ICP-MS to execute linear scan analysis across hair diameter without laborious pretreatment of hair embedding and cutting . Furthermore, the spatial resolution can be achieved down to 0.3~0.5 μm.
Secondly, we have developed a direct solid analysis method, based on the on-line isotope dilution technique coupled with laser ablation/inductively coupled plasma mass spectrometry (LA-ICP-MS), for the determination of boron in p-type silicon wafers. The laser-ablated sample aerosol was on-line mixed with an enriched boron aerosol supplied continuously using a conventional nebulization system. Upon mixing the two aerosol streams, the isotope ratio of boron changed rapidly and was then recorded by the ICP-MS system for subsequent quantification based on the isotope dilution principle. As an on-line solid analysis method, this system accurately quantifies boron concentrations in silicon wafers without the need for an internal or external solid reference standard material. Using this on-line isotope dilution technique, the limit of detection for boron in silicon wafers is 2.8 �e 1015 atoms cm–3. The analytical results obtained using this on-line methodology agree well with those obtained using wet chemical digestion methods for the analysis of p-type silicon wafers containing boron concentrations ranging from 1.0 �e 1016 to 9.6 �e 1018 atoms cm–3.
|
|---|
