Detector, atomic spectrometer electron capture

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

As noted earlier, the most widely used piece of equipment after the headspace module is a gas chromatograph, which is in turn connected to a suitable (flame ionization, electron capture, mass spectrometric, atomic absorption, atomic emission) detector. Some high-resolution detectors including mass spectrometers have been directly connected to the HS module. 

Besides the universal detector systems, for example electron capture, flame ionisation and thermal conductivity usually coupled with gas chromatographic columns, various other detectors are now being used to provide specific information. For example, the gas chromatograph/mass spectrometer couple has been used for structure elucidation of the separated fractions. The mechanics of this hybrid technique have been described by Message (1984). Other techniques used to detect the metal and/or metalloid constituents include inductively coupled plasma spectrometry and atomic absorption spectrometry. Ebdon et al. (1986) have reviewed this mode of application. The type and mode of combination of the detectors depend on the ingenuity of the investigator. Krull and Driscoll (1984) have reviewed the use of multiple detectors in gas chromatography. 

Pervaporators are amenable to coupling to any type of detector via an appropriate interface such as a transport tube, a microcolumn packed with adsorptive or ion-exchange material, or a gas liquid separator. The acceptor stream can be either liquid or gaseous depending on the characteristics of the detector. The detectors most frequently used are the spectroscopic - atomic or molecular, electroanalyti-cal (potentiometric, voltammetric), electron capture, and flame ionization types. The low selectivity of some of these detection techniques is overcome by that of the pervaporation step, endowing the overall analytical process with the selectivity required for the analysis of complex matrices. The potential use of the pervaporation technique for sample insertion into water-unfriendly detectors such as mass spectrometers or devices such as those based on microwave-induced plasma remains unexplored. 

Several detectors are used for VOCs analysis by GC flame ionization detector (FID), photo ionization detector (PID), electron capture detector (BCD), electrolytic conductivity detector (ELCD), mass spectrometer detector (MSD or MS), and Fourier-transform infrared detector (FTIRD). For the in-depth reviews of the detectors, readers are directed to Refs. [52-54]. Examples of ICP-MS or microwave-induced plasma atomic emission spectrometry (atomic emission detector, AED) have been reported as detection technique after chromatographic separation [55,56]. Current trends and developments in GC analysis of VOCs have been recently reviewed by the group of Dewulf [16,57]. Mass spectrometer detectors allow low detection limits in single/selected ion monitoring (SIM) and a qualitative confirmation by full scan mode or by means of other ion selected as qualifier. 

Several other methods have been reported for the analysis of tetraalkylleads in gasoline using gas chromatography. The methods of detection included an electron capture detector >a flame-emission detector, and a hydrogen-rich flame ionization detector. An atomic-absorption spectrometer has been used as a detector for GC391. 

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