Microwave plasma emission

Element-specific detection combined with capillary GC has become a key technique in the chemical communication studies of our laboratory. An effective detector of this type is based on the microwave plasma emission (Wylie and Quimby 1989), with a tunable selectivity for several elements and a prominent sensitivity for sulfur-containing compounds, which is significantly greater than... 

The AFD is selective to arsenic (53)—also the microwave plasma emission detector (54)— but the response is poor. For practical As determination, the colorimetric or neutron activation techniques are preferable. 

Skogerboe R. K. and Coleman G. N. (1976) Microwave plasma emission spectrometry, Anal Chem 48 611A-622A. 

Such large amounts of data can only be sensibly and rapidly analysed and compared with reference spectra using microprocessors such as the fast 32 bit processors in PCs. The main systems in use today are discussed below, and in addition to the above mentioned techniques the microwave induced plasma (MIP) detector, a helium microwave plasma emission source coupled to a GC and an optical emission spectrometer are reviewed. 

S.A. Estes, PC. Uden, M.D. Rausch, and R.M. Barnes. Fused silica capillary GC separation and element selective microwave plasma emission detection of volatile organometallics. JHRCandCC, 3, 471 (1980). 

HPLC-QFAAS is also problematical. Most development of atomic plasma emission in HPLC detection has been with the ICP and to some extent the DCP, in contrast with the dominance of the microwave-induced plasmas as element-selective GC detectors. An integrated GC-MIP system has been introduced commercially. Significant polymer/additive analysis applications are not abundant for GC and SFC hyphenations. Wider adoption of plasma spectral chromatographic detection for trace analysis and elemental speciation will depend on the introduction of standardised commercial instrumentation to permit interlaboratory comparison of data and the development of standard methods of analysis which can be widely used. 

With the exception of GC-MIP-AES there are no commercial instruments available for speciation analysis of organometallic species. Recently, a prototype automated speciation analyser (ASA) for practical applications was described [544,545], which consists of a P T system (or focused microwave-assisted extraction), multicapillary GC (MC-GC), MIP and plasma emission detection (PED). MCGC-MIP-PED provides short analysis times ([Pg.676]

Nearly every area of measurement science can boast of progress in measuring ever-smaller quantities of chemicals, but several stand out in their stunning trace-analysis capabilities. Trace-metal analysis has come to be dominated by methods that volatilize the sample and then either measure its spectroscopic emission or absorption, or measure the masses of the gaseous metal ions using mass spectrometry. Volatilization is accomplished by various thermal means that include flames, furnaces, and inductively coupled or microwave plasmas. The com-... 

Lobinski et al. [72] optimized conditions for the comprehensive speciation of organotin compounds in soils and sediments. They used capillary gas chromatography coupled to helium microwave induced plasma emission spectrometry to determine mono-, di-, tri- and some tetraalkylated tin compounds. Ionic organotin compounds were extracted with pentane from the sample as the organotin-diethyldithiocarbamate complexes then converted to their pentabromo derivatives prior to gas chromatography. The absolute detection limit was 0.5pg as tin equivalent to 10-30pg kg-1. 

River and marine sediments, soils Bu3Sn BujSn BuSn Capillary glc-helium microwave induced plasma emission spectrometric detection 0.0001-0.0003 [72] ... 

Further designs of ion sources applied in plasma spectroscopy such as electrodeless microwave induced plasmas (MIPs) operating in a noble gas atmosphere at low power (mostly below 200 W) or capacitively coupled microwave plasma using Ar, He or N2 the as plasma gas (at 400-800 W) were described in detail by Broekaert.33 Microwave plasmas produced by a magnetron are operated at 1-5 GHz. Their special application fields for selected elements and/or element species are based (due to the low power applied) in atomic emission spectrometry.33... 

It is possible to extend the principle of photometric emission (FPD) by replacing the flame with a microwave plasma that has a temperature high enough to induce any element to radiate light. This is equivalent to atomic emission where each solute is atomised and gives rise to specific emission bands. 

Bulska, E., Emteborg, H., Baxter, D.C., Freeh, W., Elligsen, D. and Thomassen, Y. (1992) Speciation of mercury in human whole blood by capillary gas chromatography with a microwave-induced plasma emission detector system following complexometric extraction and butylation. Analyst, 117, 657-663. 

Lobinski, R., Dirkx, W.M.R., Ceulemans, M. and Adams, F.C. (1992) Optimization of comprehensive speciation of organotin compounds in environmental samples by capillary gas chromatography helium microwave-induced plasma emission spectrometry. Anal. Chem., 64, 159-165. 

Buffington, R., GC-Atomic Emission Spectroscopy Using Microwave Plasmas, Hewlett Packard Corp., Avondale, PA, 1988. 

Chiba et al. [749] used atmospheric pressure helium microwave induced plasma emission spectrometry with the cold vapour generation technique combined with gas chromatography for the determination of methylmercuiy chloride, ethylmercury chloride and dimethylmercury in sea water following a 500-fold preconcentration using a benzene- cysteine extraction technique. 

Mercury Microwave plasma atomic emission spectrometer ppt [784]... 

Most chemical agents contain specific elements in common. G and V agents all contain phosphoms and blister agents, like the mustards, contain sulfur or nitrogen. The combustion of these materials yields excited atoms that emit light characteristic of these elements. The emissions are viewed through an interference filter by a photodetector. As an alternative to a flame, low-powered, inductively coupled (or microwave) plasmas have been used as emission sources. These sources have been combined with... 

Chau, Y.K., Yang, F., Brown, M. Determination of methylcyclopentadienyl-manganese tricarbonyl (MMT) in gasoline and environmental samples by gas chromatography with helium microwave plasma atomic emission detection. Appl. Organomet. Chem. 11, 31-37 (1997)... 

Because of its low specificity and sensitivity flame ionisation detection (FID) can only be used in the analysis of standard substances [37]. The same limited application is envisaged for the method with the microwave-induced plasma emission detector, which is not sensitive enough for environmental samples [2]. 

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