Argon plasma detector

Fig. 222. Dual detector chromatogram of unleaded gasoline containing MMT, column and GC conditions as in Figure 221, 5 xl gasoline injected. Effluent split 1 1 between flame ionization and dc argon plasma detectors. Mn 279.83nm line monitored.

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... 

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. 

Salov et al. [341] determined iodide, chloride, bromide, chlorate, bromate and iodate in potable water by high performance liquid chromatography with an inductively coupled argon plasma mass spectrometric detector. 

The nebulized sample is exitated in an argon-plasma at approximately 10000 Kelvin. A spectrometer with a polychromator system can determine several elements by measuring their specific emission wavelength with photomultipliers as sensitive detectors. The system requires one photomultiplier for each detectable element. The detection limits of this modem technique are usually between those of the Graphite-Furnace- and the Flame-AAS. The advantages of this system are the very high... 

The AED employs a microwave-induced He plasma to dissociate eluted analyte molecules to their component atoms and excite them to emit at characteristic wavelengths. This is very similar to the mechanism in the argon plasma inductively coupled plasma source (cf. Section 7.3.1). A spectrometer with a diode array detector (Figure 7.26b and c) isolates and measures the intensity of sensitive emission lines unique to each element. Depending on the relative sensitivity and proportion of atoms in the molecules, separate element response channels may display peaks in several element-selective chromatograms. These data may be combined with retention... 

Figure 7.17. Modulation of the poles (where the jr-axis is the time-of-flight axis) provides considerably better efficiency than modulation of the poles, and (as shown in the mass spectra of Pb and Bi in Figure 7.18) better mass resolution. In addition, an Ar deflection pulse provides mass selective removal of Ar ions arising from the argon plasma of the ICP source, and reduces the possibilities for saturation of the microchannelplate detectors.

The development of many alternative plasma sources has led to a resurgence of analytical atomic emission spectroscopy in recent years. The major plasma emission sources used for gas chromatographic detection have been the microwave-induced helium plasma, under atmospheric or reduced pressure (MIP), and the DC argon plasma (DCP). The inductively coupled argon plasma (ICP) has been used much less for GC than as an HPLC detector [4]. 

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