Pollutants ionization energy

The characteristic ions for GC/MS identification (under electron impact ionization at 70 eV nominal energy) for some common nitrosamine pollutants are tabulated in Table 2.16.2. 

The term ionizing wet scrubber was first used by the Ceilcote Co., located in Berea, Ohio, and has found wide application in the air pollution control field. This system is a proven means for the removal of pollutants from industrial process gas streams. The IWS combines the established principles of electrostatic particle charging, image force attraction, inertial impaction, and gas absorption to collect submicron solid particles, liquid particles, and noxious and malodorous gases simultaneously. The IWS system requires little energy and its collection efficiency is high for both submicron and micron size particles. 

In addition to the above methods utilizing conventional ionization modes, the field ionization technique has appeared [75]. The very intense electric field (about 1 V/A), produced by an electrode, results in the ionization of molecules in the gas phase. This soft ionization technique is often used competitively with Cl, since it does not pollute the source and may yield sufficiently reproducible results. The transit time of ions in the source is on the order of 10 to 10 second. The radical molecular ions (M ) produced are characterized by a low internal energy, and thus can be detected easily. As a result of dispersion within the source, however, sensitivity is about two orders of magnitude lower than that of El. As in the case of El, the fragments produced by FI can furnish interesting structural data on carbohydrates, amino acids, peptides and cardenolides [76],... 

The PID is mainly used for the analysis of aromatic pollutants, for example, BTEX or PAH, or halogenated compounds in environmental applications. Many EPA methods, for example, 602, 502 or 503.1, cover priority pollutants in surface or drinking water. Typical for the PID is the detection of impurities air, also with mobile detectors. This is due to the fact that the energy of the UV lamp is sufficient to ionize the majority of organic air contaminants, but insufficient to ionize the air components oxygen, nitrogen, water, argon and carbon dioxide. 

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