Induction-Coupled Argon Plasma

Aluminum is best detected quaUtatively by optical emission spectroscopy. SoHds can be vaporized direcdy in a d-c arc and solutions can be dried on a carbon electrode. Alternatively, aluminum can be detected by plasma emission spectroscopy using an inductively coupled argon plasma or a d-c plasma. Atomic absorption using an aluminum hoUow cathode lamp is also an unambiguous and sensitive quaUtative method for determining alurninum. 

Numerous methods have been pubUshed for the determination of trace amounts of tellurium (33—42). Instmmental analytical methods (qv) used to determine trace amounts of tellurium include atomic absorption spectrometry, flame, graphite furnace, and hydride generation inductively coupled argon plasma optical emission spectrometry inductively coupled plasma mass spectrometry neutron activation analysis and spectrophotometry (see Mass spectrometry Spectroscopy, optical). Other instmmental methods include polarography, potentiometry, emission spectroscopy, x-ray diffraction, and x-ray fluorescence. 

Inductively coupled argon plasma (icp) and direct current argon plasma (dcp) atomic emission spectrometry are solution techniques that have been appHed to copper-beryUium, nickel—beryUium, and aluminum—beryUium aUoys, beryUium compounds, and process solutions. The internal reference method, essential in spark source emission spectrometry, is also useful in minimizing drift in plasma emission spectrometry (17). Electrothermal (graphite... 

The classical wet-chemical quaUtative identification of chromium is accompHshed by the intense red-violet color that develops when aqueous Cr(VI) reacts with (5)-diphenylcarba2ide under acidic conditions (95). This test is sensitive to 0.003 ppm Cr, and the reagent is also useful for quantitative analysis of trace quantities of Cr (96). Instmmental quaUtative identification is possible using inductively coupled argon plasma—atomic emission spectroscopy... 

Alcohol sulfates and alcohol ether sulfates separated by HPLC on a styrene-divinylbenzene copolymer column with 4 1 (v/v) methanol and 0.05 M ammonium acetate aqueous solution as the mobile phase were analyzed by simultaneous inductively coupled argon plasma vacuum emission spectroscopy (IPC), monitoring the 180.7-nm sulfur line as a sulfur-specific detector [294]. This method was applied to the analysis of these surfactants in untreated wastewaters. 

In Figure 8.12, the basic set-up of an ICP-MS instrument is presented as a block diagram, consisting of a sample introduction system, the inductively coupled argon plasma (ICP) and the mass-specific detector. By far the most commonly applied sample introduction technique is a pneumatic nebuliser, in which a stream of argon (typically 1 I.min ), expanding with high... 

The interaction between Ag+ and selenium in the bloodstream has been studied in vitro by means of the HPLC-inductively coupled argon plasma-mass spectrometry (ICPMS) method. The metal ions and selenide form the unit complex (AgSe) and then this unit binds to selenoprotein to form the ternary complex [(AgSe)ra] selenoprotein in the bloodstream.1042... 

Francesconi, K.A., P. Micks, R.A. Stockton, and K.J. Irgolic. 1985. Quantitative determination of arsenobe-taine, the major water-soluble arsenical in three species of crab, using high pressure liquid chromatography and an inductively coupled argon plasma emission spectrometer as the arsenic-specific detector. Chemosphere 14 1443-1453. 

R. S. Houk, V. A. Fassel, G. D. Flesch, H. J. Svec, A. L. Gray, and C. E. Taylor. Inductively Coupled Argon Plasma as an Ion Source for Mass Spectrometric Determination of Trace Elements. Anal. Chem., 52(1980) 2283-2289. 

ICAP = Inductively Coupled Argon Plasma Spectrophotometry... 

Atomic absorption provides very high sensitivity but requires careful subsampling, extensive sample preparation, and detailed sample-matrix corrections. X-ray fluorescence requires little in terms of sample preparation but suffers from low sensitivity and the application of major matrix corrections. Inductively coupled argon plasma spectrometry provides high sensitivity and few matrix corrections but requires a considerable amount of sample preparation, depending on the process stream to be analyzed. 

Gunn et al. [44] described the apphcation of a graphite-filament electrothermal vaporization apparatus as a sample introduction system for optical emission spectroscopy with an inductively coupled argon plasma source. Good detection levels were reported for the elements, and details of the interfacing requirements between the ICP and the graphite filament were explored. 

An alternative approach is to analyze the samples using procedures or instrumentation that will give the maximum amount of data for each sample. For example, recent advances in atomic spectroscopy, i.e., inductively coupled argon plasma emission spectroscopy (ICP-AES), allow 20 to 30 elements to be detected simultaneously. 

Actinide metal samples are characterized by chemical and structure analysis. Multielement analysis by spark source mass spectrometry (SSMS) or inductively coupled argon plasma (ICAP) emission spectroscopy have lowered the detection limit for metallic impurities by 10 within the last two decades. The analysis of O, N, H by vacuum fusion requires large sample, but does not distinguish between bulk and surface of the material. Advanced techniques for surface analysis are being adapted for investigation of radioactive samples (Fig. 11) ... 

Inductively coupled argon plasma (ICAP) for copper look for 1 to 2 ppm copper. Potential Solution ... 

Among the plasma sources that have been used for analytical measurements include the inductively coupled argon plasma (ICP), direct current argon plasma (DCP) and microwave induced heUum plasma (MIP). The instrumentation and I rformance of the more popular ICP source have been discussed by Barnes More rwently, Thompson and Walsh have published a book dealing with the practical aspects of ICP. 

Inductively coupled argon plasma atomizes substances at 6 000 K. 

An inductively coupled argon plasma eliminates many common interferences. The plasma is twice as hot as a conventional flame, and the residence time of analyte in the flame is about twice as long. Therefore, atomization is more complete and signal is enhanced. Formation of analyte oxides and hydroxides is negligible. The plasma is remarkably free of background radiation 15-35 mm above the load coil where sample emission is observed. 

Finally, we note that the photocorrosion process is strongly pH-dependent, occurring most readily in strongly acid solutions, and that the presence of a carboxylic acid is required for the occurrence of severe photocorrosion. In Table II we present analytical results, based on inductively coupled argon plasma (ICP) emission spectroscopy, for representative electrolyte solutions after 6-8 hr. of photo-Kolbe electrolysis with n-SrTiC anodes. It can be seen that the formation of soluble strontium and titanium species is... 

Many other analytical techniques can be coupled to mass spectrometers. These so-called hyphenated techniques, like GC-MS and LC-MS, include but are not limited to ICP-MS (inductively coupled argon plasma), SCF-MS (supercritical fluid), NMR-MS (nuclear magnetic resonance) and IR-MS (infrared). 

Gardner, W.S., Landrum, P.F. and Yates, D.A., 1982. Fractionation of metal forms in natural waters by size exclusion chromatography with inductively coupled argon plasma detection. Anal. Chem., 54 1196-1198. 

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