Microwave plasma mass spectrometry

Plasma mass spectrometry in the early 1980s made use of microwave plasmas [598]. However, as a result of the more robust character of the ICP and the related ease of sample introduction, microwave plasma mass spectrometry did not develop as a general method. However, for selected fields of application its figures of merit are interesting. 

Huang M, Hirabayashi A, Shirasaki T, Koiznmi H (2000) A multimicrospray nebulizer for microwave-induced plasma mass spectrometry. Anal Chem 72 2463-2467 Ivanovich M, Murray A (1992) Spectroscopic methods. In Uranium-Series Disequilibrium Applications to Earth, Marine, and Enviromnental Sciences, 2" Ed. Ivanovich M, Harmon RS (eds) Orfbrd Univ. Press, Oxford... 

As SFC provides gaseous sample introduction to the plasma and thus near-100 % analyte transport efficiency, coupling SFC with plasma mass spectrometry offers the potential of a highly sensitive, element-selective chromatographic detector for many elements. Helium high-efficiency microwave-induced plasma has been proposed as an element-selective detector for both pSFC and cSFC [467,468] easy hyphenation of pSFC to AED has been reported [213]. 

Other frequently used methods for determining fluoride include ion and gas chromatography [150,204,205] and aluminium monofluoride (AIF) molecular absorption spectrometry [206,207]. Less frequently employed methods include enzymatic [208], catalytic [209], polarographic [210] and voltammetric methods [211], helium microwave-induced [212] or inductively coupled plasma atomic emission spectrometry [213], electrothermal atomic absorption spectrometry [214], inductively coupled plasma-mass spectrometry [215], radioactivation [216], proton-induced gamma emission [217], near-infrared spectroscopy [218] and neutron activation analysis [219]. 

Story WC, Caruso JA. 1993. Gas chromatographic determination of phosphorus, sulfur and halogens using a water-cooled torch with reduced-pressure helium microwave-induced plasma mass spectrometry. J Anal Atomic Spectrometry 8 571-575. 

Inductively coupled plasma-mass spectrometry (ICP-MS) has seen increasing use in trace element studies of ceramics in the last two decades. While early work using weak acid extraction proved problematic (/), recent work by Kennet et al. using microwave digestion (2) and by Larson et al. using laser ablation (3) have yielded considerable advances in the application of this technique. 

Inductively coupled plasma-mass spectrometry (ICP-MS) has been utilized as a bulk technique for the analysis of obsidian, chert and ceramic compositional analyses 12-14). However, due to the high level of spatial variation of ceramic materials, increased sample preparation is necessary with volatile acids coupled with microwave digestion (MD-ICP-MS) to properly represent the variability of ceramic assemblages IS, 16). Due to the increased sample preparation and exposure to volatile chemicals, researchers have continued to utilize neutron activation analysis (INAA) as the preferred method of chemical characterization of archaeological ceramics (77). 

Figure 6.1 Bar-graph of MeHg in CRM 580. The results correspond to six replicate determinations as performed by different laboratories using various methods. MEANS indicates the mean of laboratory means with 95% confidence interval. Abbreviations-. CVAAS, cold vapour atomic absorption spectrometry CVAFS, cold vapour atomic fluorescence spectrometry ECD, electron capture detection GC, gas chromatography HPLC, high-performance liquid chromatography ICPMS, inductively coupled plasma mass spectrometry MIP, microwave induced plasma atomic emission spectrometry QFAAS, quartz furnace atomic absorption spectrometry SFE, supercritical fluid extraction.

Suyani, H., Creed, J., Caruso, J. and Satzger, R.D. (1989) Helium microwave-induced plasma mass spectrometry for capillary gas chromatographic detection speciation of organotin compounds./. Anal. At. Spectrom., 4, 777-782. 

Yang, L. and J.W. Lam. 2001. Microwave-assisted extraction of butyltin compounds from PACS-2. Sediment for quantitation by high-performance liquid chromatography inductively coupled plasma mass spectrometry. J. Anal. At. Spectrom. 16 724—731. 

Yoshinaga and Morita used isotope dilution in conjunction with ICP-MS to measure mercury in biological and environmental samples [45]. The same group used microwave-induced plasma mass spectrometry for the isotope dilution analysis of selenium in biological materials [46]. Analysis of nickel via isotope dilution and ICP-MS has been reported by Patriarca et al [47]. 

Figure 2 Schematic diagram of a typical microwave induced plasma mass spectrometry (MIP-MS) instrument.

Microwave induced plasma mass spectrometry has also been used as a detector for supercritical fluid chromatography (SFC) [113] for the separation of halogenated hydrocarbons. The design of an SFC-MIP interface must ensure that the frit restrictor temperature remains at a high temperature to prevent condensation of analytes. Stainless steel transfer lines may be used. The frit restrictor should be connected to a length of deactivated fused silica capillary, inserted through the transfer line, and positioned flush with the aluminum MIP torch inset (Fig. 10.21). 

Figure 21 Supercritical fluid chromatography microwave induced plasma mass spectrometry (SFC-MIP-MS) torch interface. (From Ref. 113.)...

J.S. Alvarado, T.J. Neal, L.L. Smith and M.D. Erickson, Microwave Dissolution of Plant Tissue and the Subsequent Determination of Trace Lanthanide and Actinide Elements by Inductively Coupled Plasma-Mass Spectrometry, Analytica Chimica Acta 322, 11-20 (1996). 

L. Noel, J. C. Leblanc, T. Guerin, Determination of several elements in duplicate meals from catering establishments using closed vessel microwave digestion with inductively coupled plasma mass spectrometry detection estimation of daily dietary intake, Food Addit. Contam., 20 (2003), 44-56. 

R. Tukai, W. A. Maher, I. J. McNaught, M. Ellwood, Measurement of arsenic species in marine macroalgae by microwave-assisted extraction and high performance liquid chromatography-inductively coupled plasma mass spectrometry, Anal. Chim. Acta, 457 (2002), 173-185. 

C. S. Chiou, S. J. Jiang, K. S. K. Danadurai, Determination of mercury compounds in fish by microwave-assisted extraction and liquid chromatography-vapor gener-ation-inductively coupled plasma mass spectrometry, Spectrochim. Acta, 56B (2001), 1133-1142. 

Kingston, H.M., Walter, P.J. The art and science of microwave sample preparations for trace and ultratrace elemental analysis. In Montaser, A. (ed.) Inductively Coupled Plasma Mass Spectrometry, pp. 33-81. Wiley-VCH, New York (1998)... 

Bhandari, S.A., Amarasiriwardena, D. Closed-vessel microwave acid digestion of commercial maple syrup for the determination of lead and seven other trace elements by inductively coupled plasma-mass spectrometry. Microchem. J. 64, 73-84 (2000)... 

Guzmn Mar, J.L., Hinojosa Reyes, L., Mizanur Rahman, G.M., Skip Kingston, H.M. Simultaneous extraction of arsenic and selenium species from rice products by microwave-assisted enzymatic extraction and analysis by ion chromatography-inductively coupled plasma-mass spectrometry. J. Agric. Food Chem. 57, 3005-3013 (2009)... 

Djingova, R., Heidenreich, H., Kovacheva, P., Markert, B. On the determination of platinum group elements in environmental materials by inductively coupled plasma mass spectrometry and microwave digestion. Anal. Chim. Acta 489, 245-251 (2003)... 

As noted earlier, USNs have been employed for sample insertion into atomic spectrometers suoh as flame atomio absorption spectrometry (FAAS) [9,10], electrothermal atomic absorption speotrometry (ETAAS) [11], atomic fluorescence spectrometry (AFS) [12,13], induotively ooupled plasma-atomic emission spectrometry (ICP-AES) [14,15], inductively coupled plasma-mass spectrometry (ICP-MS) [16,17] and microwave induced plasma-atomic emission spectrometry (MIP-AES) [18,19]. Most of the applications of ultrasonic nebulization (USNn) involve plasma-based detectors, the high sensitivity, selectivity, precision, resolution and throughput have fostered their implementation in routine laboratories despite their high cost [4]. 

Olson, L.K. Caruso, J.A. The helium microwave-induced plasma—An alternative ion-source for plasma-mass spectrometry. Spectrochim. Acta, Part B 1994, 49, 7-30. 

Okamoto Y. (1994) High-sensitivity microwave-induced plasma mass spectrometry for trace element analysis, J Anal At Spectrom 9 745-749. 

Total Hg determined by inductively coupled plasma mass spectrometry (ICPMS) after microwave digestion with HNO, and reduction with SnCl, (Lab.09)... 

Laborious, yet very reliable, is the complete extraction of the dried, mortared and homogenized sediment sample using appropriate acids. Usually a microwave pressure extraction in a closed system composed of PTFE or a similarly inert and resistant material is applied for this purpose nowadays. With this method, all the sedimentary constituents are dissolved without exception by applying various mixtures of HF, HCl and HNO (HCLO can be avoided in most cases) at temperatures between 250 and 260 °C and a pressure ranging from 30 to 50 bars. In the ultimately received, slight nitric solution - hydrofluoric acid is left to evaporate in the course of the procedure -practically all elements (including the rare earth elements) can then be analyzed markedly above their limit of detection by atom absorption spectrometry (AAS), optical plasma emission spectrometry (ICP-OES) and/or plasma mass spectrometry (ICP-MS). 

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