Studies on the Improvement of Sensitivity and Precision in Atomic Emission Spectrometry with Inductively Coupled Plasma (ICP) and Microwave Induced Plasma (MIP)

点击翻译按钮获取中文摘要

Analytical plasmas such as inductively coupled plasma (ICP) and microwave induced plasma (MIP) have become powerful atomization/excitation sources for atomic emission spectrometry (AES) for the determination of trace metals and nonmetals. In this project, the AES method coupled with ICP and MIP has been investigated to improve the sensitivity and precision of the determination of, in particular, nonmetals. Several worthy results obtained in this study are summarized as follows :1. The analytical potentials of ICP-AES for the determination of nonmetals has been investigated using atomic emission lines in the vacuum ultraviolet (VUV) spectral region. In this work, the practical utility of the VUV lines (B 182.64 nm, S 180.73, 182.04, 182.62 nm) as well as the air normal ultraviolet line (B 208.96 nm) was examined using a conventional solution nebulization. A sensitive method with ICP-AES in the VUV spectral region has been successfully applied to the determination of boron and sulfur in … More several steel reference standard materials (RSM'S).2. In this study, a new instrumentation has been made for the atmospheric pressure helium MIP-AES employing not only a Beenakker-type resonant cavity but also a newly-constructed "surfatron" cavity. Next, in addition, the experimental system has been modified in order to measure emission lines lying in the VUV region of the spectrum by a simple nitrogen-purged optical system.3. In the atmospheric pressure helium MIP-AES, firstly the indirect determination of iodine has been examined and developed utilizing continuous-flow cold-vapor generation of mercury. As an alternative, the gas-phase sample introduction technique has been investigated for the direct determination of iodine by using the 183.04- and 206.16-nm lines, and the best attainable detection limit for iodine was 0.74 ng/ml. The latter method has been applied to the determination of total iodine in brines and sea waters with success.4. In addition to iodine, the developed continuous-flow gas-phase sample introduction for MIP-AES has been extended for the determination of bromine and sulfur with introduction of elemental bromine from bromide, and hydrogen sulfide and sulfur dioxide from sulfide and sulfite ions, respectively. The results for the determination of bromine in several sea waters by the proposed method are in good agreement with those obtained by ion chromatography and inductively coupled plasma-mass spectrometry. Less