Gas-chromatographic detector

H. Dressier, "Selective Gas Chromatographic Detectors", Elsevier, Amsterdam, 1986. 

The flame ionization detector Is the most popular of the flame-based detectors. Apart from a reduction in sensitivity compared to expectations based on gas chromatographic response factors [138] and incompatibility with the high flow rates of conventional bore columns (4-5 mm I. 0.), the flame ionization detector is every bit as easy to use in SFC as it is in gas chromatography [148,149]. It shows virtually no response to carbon dioxide, nitrous oxide and sulfur hexafluoride mobile phases but is generally incompatible with other mobile phases and mixed mobile phases containing organic modifiers except for water and formic acid, other gas chromatographic detectors that have been used in SFC include the thermionic ionization detector (148,150], ... 

The high sensitivity and selectivity of some gas chromatographic detectors are used to advantage in the measurement of organic mercury compounds. In the simplest approach, methyl mercury is extracted from seawater and converted to the iodide for electron capture gas chromatography [74],... 

M Dressier. Selective Gas Chromatographic Detectors. Amsterdam Elsevier, 1986, pp 1-319. 

Common GC mobile phases (see Table 13.2) are hydrogen, argon, helium, nitrogen, and air. Helium and nitrogen are the most commonly used. Because gas chromatographic detectors are extremely sensitive and it is desirable to keep the noise level as low as possible, it is always advisable to use very high-purity gas as the mobile phase. 

MS as a gas chromatographic detector has become much simpler to operate in the past decade. Nearly all control of the detector is performed through a data system with similar look-and-feel to other chromatographic data systems. Components such as ion sources now have less than 10 parts, making periodic cleaning and maintenance much simpler than in the past. Finally, the pricing of mass selective detectors is now similar to other selective detectors. It is likely that MS will eventually supplant most of the other selective detectors. 

No other detector till date has surpassed the flame ionization detector (FID) as a universal gas chromatographic detector. It hardly meets, all the characteristic features of TCD in terms of simplicity, stability, and versatility besides having two distinctly positive plus points ... 

G.A. Eiceman, E.G. Nazarov, R.A. Miller, E.V. Krylov and A.M. Zapata, Micro-machined planar field asymmetric ion mobility spectrometer as a gas chromatographic detector, Analyst 127(4) (2002) 466-471. 

Haas JW, Buchanan MV, Wise MB. 1988. Differentiation of polycyclic aromatic hydrocarbons using a multimode ionization gas chromatographic detector. I Chromatogr Sci 26(2) 49-54. 

The use of various sorbents and desorption systems permits (often necessitates) gas chromatographic detectors other than the most commonly used flame detector or electron capture detector. The use of a selective detector can greatly simplify a difficult analytical problem by reducing interferences and background peaks. Many applications are discussed in the literature (21,22,23,24). 

With today s advanced analytical procedures, it is possible to describe the composition of these fuels in considerable detail. By combining several sequenced liquid chromatographic separations with gas chromatography-mass spectroscopy and by using specific gas chromatographic detectors for sulfur compounds, it has been possible to identify the majority of individual sulfur species in some fuels (12-19). A typical separation scheme is shown... 

It is useful to consider gas chromatographic detectors in this way, and to compare them to other analytical instruments ... 

Several gas chromatographic detectors are sensitive to changes in the flowrate of the carrier gas. Any changes in flow rate cause the baseline to be displaced. These displacements make quantification quite difficult especially since the response of certain detectors such as thermal conductivity also changes with changes in flowrate. When an accuracy of 1% in quantitative analysis is required, the flowrate should not fluctuate more than 0.2 percent (see Chapter 4). 

Mistry, B.S., Reineccius, G.A., and Jasper, B.L. 1994. Comparison of gas chromatographic detectors for the analysis of volatile sulfur compounds in foods. In Sulfur Compounds in Food (C.J. Mussinan and M.E. Keelan, eds.) pp. 8-21. American Chemical Society, Washington, D.C. 

Based on the method of internal normalization of peak areas, the percentage composition (less the diethyl ether solvent shown as the initial large component in Figures 1 and 2) of odor concentrates was estimated. The average composition of samples of odor isolates from individual preparations as well as from several different preparations of the same type—i.e., concurrent or noncurrent—was determined on the basis of all preparations which could be compared on a fair analytical basis (same gas chromatographic detector, column, and conditions). These results were then combined (traps plus distillate) to provide the rough estimations shown in Table IV. These data represent the best estimation of the composition of the total volatile odor concentrates from each processing method studied. 

Llopart-Vizoso et al. [ 114] determined phenols and cresols in soil by direct acetylation followed by gas chromatography headspace analysis. Danis and Albanis [115] also used a technique based on acetylation-gas chromatography. Three gas chromatographic detectors were employed flame ionisation, electron capture and mass spectrometric. 

Baena, J.R., M. Gallego, M. Valcarcel, et al. 2001. Comparison of three coupled gas chromatographic detectors (MS, MIP-AES, ICP-TOFMS) for organolead speciation analysis. Anal. Chem. 73 3927-3934. 

Dressier, M. Selective Gas Chromatographic Detectors Elsevier Amsterdam, 1986, Chapter 7. 

Bowman, M. C., Beroza, M. Gas chromatographic detector for simultaneous sensing of phosphorus and sulfur containing compounds by flame photometric. Anal. Chem. 40, 1448 (1968). 

The combination of these microextraction techniques that combine sampling, extraction and pre-concentration into a sigle step, with high sensitive gas chromatograph detectors such as mass spectrometer is the way to determine compounds at levels of ng L 1 that could be important for wine aroma characterization. 

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