Corona discharge, described

VOC emissions of paper mills and wood processing plants usually contain a significant amount of terpenes, especially a-pinene (CioHie see Table 11-4). Effective plasma removal of a-pinene (CioHig) has been demonstrated in pulsed corona discharges described in Section 11.8.3 at temperatures of 70-200°C (Sobacchi et al., 2003), which is illustrated in Fig. 11-66 for different pulse frequencies corresponding to different levels of discharge power (the SEI is 20, 50, and 100 Wh/m for the frequencies 266, 667, and 1450 Hz). 

Articles fabricated from FEP resins can be made bondable by surface treatment with a solution of sodium in Hquid ammonia, or naphthalenyl sodium in tetrahydrofuran (64) to faciUtate subsequent wetting. Exposing the surface to corona discharge (65) or amines at elevated temperatures in an oxidizing atmosphere (66) also makes the resins bondable. Some of the more recent work is described in References 67—69. 

In the positive ion mode, the electrons from the corona discharge produce primary ions (mainly NJ, OJ , H20+", and NO+") through the El of nitrogen and oxygen, as described below ... 

There are two more or less exploited types of corona devices—a pin corona discharge device and a wire corona discharge device. These devices are well described by Vaezi-Nejad and Juhasz [3]. 

Today, corona discharge is the electrical method used most widely and is one of the most popular for preparing the surfaces of polyolefin films. It relies on establishing a corona discharge between an electrode and an earthed roller covered by a dielectric layer the film is passed over the roller and the discharge renders the surface of the film receptive to inks. Sherman and co-authors12 described the theoretical electrical relationships in the treatment equipment and by means of the Lissajous technique for measuring power demonstrated how much true power was dissipated in the material under treatment. Table XX lists some relevant patents. 

The use of static SIMS for the characterization of surfaces of polypropylene (PP), PTFE and a PMDA-ODA type poly-imide is described. Interfaces between evaporated copper or chromium films onto PTFE and polyimide were also analyzed. Some of the polymer substrates were modified by ion beams, corona discharge in air or plasma treatments in air, At and H2. It is demonstrated that SIMS is highly complementary to XPS for the analysis of such modified surfaces, in that effects such as crosslinking, unsaturation and formation of low-molecular weight material at surfaces can be detected. 

Mass spectrometry (MS) has become one of the most important analytical tools employed in the analysis of pharmaceuticals. This can most likely be attributed to the availability of new instrumentation and ionization techniques that can be used to help solve difficult bioanalytical problems associated with this field (1-8). Perhaps the best illustration of this occurrence is the development of electrospray (ESI) and related atmospheric-pressure ionization (API) techniques, ion-spray (nebulizer-assisted API), turbo ionspray (thermally assisted API), and atmospheric pressure chemical ionization (APCI nebulization coupled with corona discharge), for use in drug disposition studies. The terms ESI and ionspray tend to be used interchangeably in the literature. For the purpose of this review, the term API will be used to describe both ESI and ionspray. In recent years there has been an unprecedented explosion in the use of instrumentation dedicated to API/MS (4,6,8-14). API-based ionization techniques have now become the method of choice for the analysis of pharmaceuticals and their metabolites. This has made thermospray (TSP), the predominant LC/MS technique during the 1980s, obsolete (15). Numerous reports describing the utility of API/MS for pharmaceutical analysis have appeared in the literature over the last decade (7). The... 

Atmospheric pressure chemical ionization uses an atmospheric pressure ionization interface. The interface is similar to that used for ESI, but a corona discharge is used to ionize the analyte in an atmospheric pressure region. (Note This is different than the chemical ionization source described in Chapter 20 for GC-MS.) The gas-phase ionization of less polar analytes is more efficient than with ESI, but the mass range is hmited to about 2000 daltons. ESI and APCI are complementary. APCI has largely replaced thermal ionization as an interface in commercial instraments. 

Zakharov and Sukhushin described the initiation of detonation [18] in TIN3 and CuN by voltage impulses with durations of 10 sec. Pressed pellets of low porosity were held on a planar metal electrode and contacted with a second, spherical metal electrode in a medium of silicon oil to prevent corona discharges. Different electrode materials were introduced by varying the material of the plane electrode. (Figures 3 and 4). With the plane electrode positive (anode), the... 

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