Photoionization detection

ECD = electron capture detector FID = flame ionization detection GC = gas chromatography HECD = Hall electrolytic conductivity detector HRGC = high-resolution gas chromatography HSD = halogen-specific detector H2SO4 = sulfuric acid MS = mass spectrometry NR = not reported PID = photoionization detection UV = ultraviolet detection... 

The selective hydride generation-gas chromatographic method [121] using photoionization detection discussed in section 12.10.2.1 for the determination of arsenic III and arsenic V has been applied to the determination of down to 3.3pmol L 1 of antimony (Sb III, SbV) in sediments. 

Langhorst ML, Nestrick TJ. 1979. Determination of chlorobenzenes in air and biological samples by gas chromatography with photoionization detection. Anal Chem 51 2018-2025. 

Abbreviations GC/FID, gas chromatography/flame ionization detection GC/MS, gas chromato-graphy/mass spectrometry GC/PID, gas chromatography/photoionization detection Includes groundwater, sludges, caustic and acid liquors, waste solvents, oily wastes, mousses, tars, fibrous wastes, polymeric emulsions, filter cakes, spent carbons, spent catalysts, soils, and sediments... 

Lindqvist subsequently described a similar system for the determination of HN03 (67). HN03 was collected on an Al2(S04)3-coated quartz denuder. The thermally desorbed NOx was determined by gas chromatogra-phy-photoionization detection. Subsequently Tanner et al. (68) simplified and fully automated the overall system configuration. A 51- X 0.4-cm quartz denuder tube was solution-coated with 20% w/v Al2(S04)3 and used at a very low Q (0.1 L/min). The desorption step involved heating to 500 °C for 1 min the liberated NOx was determined by a chemiluminescence monitor. Although laboratory results were attractive, field intercomparisons with a number of other methods indicated low and variable results the reasons for this discrepancy could not be identified with certainty. 

Cutter, L.S., Cutter, G.A. and Diego-McGlone, M.L.C. (1991) Simultaneous determination of inorganic arsenic and antimony species in natural waters using selective hydride generation with gas chromatographic/photoionization detection. Anal. Chem., 63, 1138-1142. 

As discussed in Chapter 6, the primary method of analyzing benzene in body fluids and tissues is gas chromatography (GC) in conjunction with either mass spectrometry (MS), photoionization detection (PID), or flame ionization detection (FID). For detection of benzene metabolites, both GC/FID and high-performance liquid chromatography (FIPLC) with ultraviolet detection (UV) have been used. A recent article describes the development of simple and sensitive methods for determination of blood and urinary benzene levels using gas chromatography headspace method (Kok and Ong 1994). 

Screening methods are available for analysis of benzene in feces and urine (Ghoos et al. 1994) and body fluids (Schuberth 1994). Both employ analysis by capillary GC with an ion trap detector (ITD). Benzene in urine has been determined by trapping benzene stripped from the urine on a Carbotrap tube, followed by thermal desorption GC/flame ionization detection (FID). The detection limit is 50 ng/L and the average recovery is approximately 82% (Ghittori et al. 1993). Benzene in urine has also been determined using headspace analysis with capillary GC/photoionization detection (PID). The detection limit is 40 ng/L (Kok and Ong 1994). 

Kok PW, Ong CN. 1994. Blood and urinary benzene determined by headspace gas chromatography with photoionization detection application in biological monitoring of low-level nonoccupational exposure. Int Arch Occup Environ Health 66(3) 195-201. 

Further reactions of the clusters are terminated upon supersonic expansion from the reactor into vacuum. Thus except for unimolecular decomposition during the flight time to the photoionization detection zone ( 500 /xs), the distribution of the species in the beam is frozen. 

Jalali-Heravi, M. and Garkani-Nejad, Z. (2002b) Prediction of relative response factors for flame ionization and photoionization detection using self-training artificial neural networks./. Chromat., 950, 183-194. 

Vien SH, Fry RC. 1988. Ultrasensitive, simultaneous determination of arsenic, selenium, tin, and antimony in aqueous solution by hydride generation gas chromatography with photoionization detection. Anal Chem 60 465-472. 

This mode of ionization is associated with photon induced ionization at around 10 eV. In place of the corona assembly, a UV lamp is used as for the photoionization detection (cf section 2.7.5). This process, which yields few fragments, is only interesting for molecules of low polarity. 

We will discuss the application of multistep laser excitation and ionization to determine the physical properties mentioned above in the lanthanides and actinides with emphasis on the determination of accurate ionization potentials. The discussion will point out how the laser techniques can circumvent many of the experimental obstacles that make these measurements difficult or impossible by conventional spectroscopy. The experimental apparatus and techniques described can be employed to measure all the properties and they are typical of the apparatus and techniques employed generally in multistep laser excitation and ionization. We do not claim completeness for literature cited, especially for laser techniques not involving photoionization detection. 

Method 506 determination of phthalate and adipate esters in drinking water by liquid-liquid extraction or liquid-solid extraction and gas chromatography with photoionization detection. In Revision LI, National Exposure Research Laboratory, Office of Research and Development, Munch, J. W., Ed., Environmental Protection Agency (EPA), Cincinnati, 1995. 

Ionization of molecules / Flame ionization detection (FID) 1 Photoionization detection (PID) OC- OC... 

A number of very useful and practical element selective detectors are covered, as these have already been interfaced with both HPLC and/or FIA for trace metal analysis and spe-ciation. Some approaches to metal speciation discussed here include HPLC-inductively coupled plasma emission, HPLC-direct current plasma emission, and HPLC-microwave induced plasma emission spectroscopy. Most of the remaining detection devices and approaches covered utilize light as part of the overall detection process. Usually, a distinct derivative of the starting analyte is generated, and that new derivative is then detected in a variety of ways. These include HPLC-photoionization detection, HPLC-photoelectro-chemical detection, HPLC-photoconductivity detection, and HPLC-photolysis-electrochemical detection. Mechanisms, instrumentation, details of interfacing with HPLC, detector operations, as well as specific applications for each HPLC-detector case are presented and discussed. Finally, some suggestions are provided for possible future developments and advances in detection methods and instrumentation for both HPLC and FIA. 

Much less thoroughly investigated, but showing considerable promise, is the use of flophemesyl derivatives to improve detection limits in GC analyses with photoionization detection (PID) [452, 453]. Simple aliphatic alcohols dissoved in acetonitrile, pyridine or triethyl-amine were found to react very rapidly with flophemesyl... 

High-energy photons can remove an electron from a sample molecule and generate a molecular ion. Inexpensive gas discharge lamps, originally developed for photoionization detection in gas chromatography, are suitable sources of photons, e.g., 10.0 eV photons from a krypton discharge lamp. 

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