Microwave emission detector

Emteborg, H., Baxter, D.C. and Freeh, W. (1993) Speciation of mercury in natural waters by capillary gas chromatography with a microwave emission detector following preconcentration using a dithiocarbamate resin microcolumn installed in a closed flow injection a system. Analyst, 118, 1007-1013. 

The spectral emission as a source of selective signal is also obtained by a microwave discharge, which constitutes the principle of the microwave emission detector [52]. 

Abbreviations FID flame ionization detector BCD electron capture detector FPD flame photometric detector MS mass spectrometer MED microwave emission detector AAS atomic absorption spectrometer. 

AAS = atomic absorption spectrometry APDC = ammonium pyrrolidine dithiocarbamate APHA = American Public Health Association EPA = Environmental Protection Agency FPD = flame photometric detection ICP/AES = inductivity coupled plasma atomic emission spectroscopy MED = microwave emission detector MIBK = methyl isobutyl ketone NIOSH = National Institute for Occupational Safety and Health XRF = x-ray fluorescence... 

Volatile complexes of organic compounds of metals are, however, used more widely in GC analysis [45, 46, 211]. The main adwmti e of the GC analysis of volatile compounds of metals is the possibility of analysing trace amounts of metals with the use of ECDs and microwave emission detectors. When detectors of this type were used, GC methods were compared with such methods as neutron-activation analysis and atomic-absorption spectroscopy. The field of apphcation for this method is indicated in Table 1.5, illustrating the analysis of trace amounts of elements in the form of volatile complexes and compiled from data pubUshed in the literature. 

The microwave emission detector has been demonstrated to be useful for the detection of organoberyllium compounds ... 

Various workers (Reamer et al, and Quimby et al ) have examined the applicability of helium in microwave glow discharge detectors for the detection of organolead compounds leaving a gas chromatographic column. A microwave emission detector (MED) was firsi described by McCormack et al. ... 

The construction of a gas-chromatograph-microwave emission detector system incorporates the basic units, the source, the monochromator readout system and the interface to the gas chromatograph. Quimby et al used an atmospheric pressure helium plasma for the reasons discussed above. No monochromator operated over a wavelength range 190-800 nm so that not only lead but other elements (discussed elsewhere) could be monitored. Generally, selectivity can be... 

In Figure 177 is shown a block diagram of the gas chromatograph-microwave emission detector system. The system was designed to allow detection with both the flame ionization detector (FID) and microwave emission detector (MED) simultaneously. The effluent from the column was split using a low dead volume 1/16 in tee located inside the column oven. From the splitter, one third of the effluent was directed to the FID, and the balance to the MED. The split ratio was adjusted by crimping the transfer line to either the FID or the MED, as described by McLean et al, 459. All transfer lines were 1/16 in o.d. X 0.01 in i.d. stainless steel. The portion of the column effluent directed to the MED passed through a heated transfer line which extended from inside the column oven to the interface oven. 

Feldman and Batistoni have described a design of a glow discharge tube as a detector for gas chromatography of organochromium compounds. This technique is described in detail in the section on arsenic. The microwave emission detector has been demonstrated to be useful for the detection of organochromium compounds, 13, 454. 

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