Chemical analysis plasmas

Chemical Analysis. Plasma oxidation and other reactions often are used to prepare samples for analysis by either wet or dry methods. Plasma excitation is commonly used with atomic emission or absorption spectroscopy for quaUtative and quantitative spectrochemical analysis (86—88). 

In plasma chromatography, molecular ions of the heavy organic material to be analy2ed are produced in an ionizer and pass by means of a shutter electrode into a drift region. The velocity of drift through an inert gas at approximately 101 kPa (1 atm) under the influence of an appHed electric field depends on the molecular weight of the sample. The various sonic species are separated and collected every few milliseconds on an electrode. The technique has been employed for studying upper atmosphere ion molecule reactions and for chemical analysis (100). 

The samples were characterized by chemical analysis induced coupled plasma and atomic absorption techniques apparatus), nitrogen adsorption isotherms (at 77 K), XRD patterns ( Siemens diffractometer and (3uKa radiation), SEM observations (Hitachi S800 apparatus of the University C. Bernard, Lyon I) and TGA-DTA (Setaram 92-12 apparatus). The IR spectra were recorded with a Bruker IPS 48 FTIR spectrometer. 

The nature of the surface of organogermanium films, obtained by magnetically enhanced rf-plasma deposition from tetraethylgermane, was examined by ESCA (electron spectroscopy for chemical analysis) and FTIR methods56. 

This presentation will summarize developments in laser ablation with emphasis on LIBS (laser induced breakdown spectroscopy) and inductively coupled plasma mass spectrometry (ICPMS) as analytical tools for real time chemical analysis (Fig. 1) (Russo et al. 

The samples were air-dried at room temperature, sieved to < 63 pm and analysed by x-ray diffraction (XRD) and scanning electron microscopy combined with an energy dispersive system (SEM-EDS). For chemical analysis, samples were submitted to an extraction with Aqua Regia and analysed by inductively coupled plasma-optical emission spectrometry (ICP/OES). Firing experiments were performed following the procedure described by Brindley Brown (1980). 

Hart, F. A. and Adams, S. J. (1983). The chemical-analysis of Romano-British pottery from the Alice Holt forest, Hampshire, by means of inductively-coupled plasma emission-spectrometry. Archaeometry 25 179-185. 

Figure 6.3 Diagrammatic representation of the dry reagent strips known as reagent carriers, which are used in the Boehringer Reflotron System for the chemical analysis of blood samples. Red blood cells are removed in the separating layer and the plasma passing into the glass fibre transport layer is analysed. The magnetic code carries information about the analytical procedure.

Kee, R. J. Rupley, F. M. Meeks, E. and Miller, J. A. Chemkin-III A Fortran Chemical Kinetics Package for the Analysis of Gas-Phase Chemical and Plasma Kinetics , Sandia National Laboratories Report SAND96-8216, 1996. 

Gillson GR, Douglas DJ, Fulford JE, Halligan KW, Tanner SD (1988) Nonspectroscopic interelement interferences in inductively coupled plasma mass spectrometry. Anal Chem 60 1472-1474 Gonfiantini R, Valkiers S, Taylor PDP, De Bievre P (1997) Adsorption in gas mass spectrometry. II Effects on the measurement of isotope amount ratios. Int J Mass Spectrom Ion Proc 171 231-242 Habfast K (1997) Advanced isotope ratio mass spectrometry. I magnetic isotope ratio mass spectrometers. In Modem Isotope Ratio Mass Spectrometry. Chemical Analysis Vol. 145. Platzner IT (ed). John Wiley and Sons, Chichester UK, p 11-82... 

Hild, D.N. and Schwart2, P. (1992a). Plasma treated ultrahigh strength polyethylene fibers, part I. Characterization by elctron spectroscopy for chemical analysis. J. Adhesion Sci. Technol. 6, 879 896. 

A universial anticoagulant does not exist, and it is therefore necessary to use, in clinical chemical analysis, serum or plasma prepared with a variety of anticoagulants. The role of the anticoagulant and preservatives on the observed value has been reviewed by Caraway (C2, C4) and by Winsten (Wll). 

The rehydrated products were characterized by chemical analysis (ICP Plasma 400 Perkin Elmer), powder-XRD measurements (URD 63 Seifert) in a range from 4° to 40° (20), N2-Adsorption (Sorptomatic 1900 Porotec), Hg-porosimetry, He-density and Scanning Elektron Microscopy (SEM). 

The Si/Al ratios of samples were determined by conventional chemical analysis. The contents of boron and sodium were analyzed by using the inductively coupled plasma (ICP) technique. 

The determination of specific phosphorus compounds in thin films is important. Only through wet chemical analysis was it possible to first discover the presence and then to accurately measure the quantities of P2Os, P203, and phosphine found in plasma, plasma-enhanced, LPO-LTO (low-pressure oxide-low-temperature oxide), and CVD (chemical vapor deposition) processes (3). Methods such as X-ray or FTIR spectroscopy would have seen all phosphorus atoms and would have characterized them as totally useful phosphorus. In plasma and plasma-enhanced CVD films, phosphine is totally useless in doping processes. 

For the synthesis of zinc ferrite (ZnFe204) of stoichiometric composition CFD and HPS samples were mixed in an appropriate ratio. From the chemical analysis the Fe/Zn molar ratio of the mixture was 2.18. To override the problem of the coohng effect of volatiles on the plasma (mentioned above), prior to mixing HPS sample was preheated at 300 °C to reduce its volatile (H2O) content. Conditions of the plasma treatments can be seen in Table 3. In order to improve heat transport between the hot gases... 

The availability of inductively coupled plasma mass spectrometry (ICPMS) has provided a method of detection of many impurities at very low concentrations directly in the organometallic compound itself. ICP mass spectrometry is a relatively recently developed chemical analysis technique that is useful in the detection of trace element concentrations in a liquid or solid matrix. ICPMS can measure the presence of almost all elements simultaneously, thus giving a detailed, semiquantitative picture of the impurity distribution in the sample. This technique has sensitivities for many elements in the parts-per-billion to parts-per-trillion range. It has the advantage that it is extremely sensitive and can analyze small samples (10 ml or less) of organometallics directly. The ICPMS technique employs a plasma to dissociate the material to be characterized into... 

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