![]() Marsili R (1997) Techniques for analyzing food aroma. In: Schreier P (ed) Analysis of volatiles: New methods and their application. Leahy MM, Reineccius GA (1984) Comparison of methods for the analysis of volatile compounds from aqueous model systems. Kazeniak SJ, Hall RM (1970) Flavor chemistry of tomato volatiles. Naturwissenschaften 52:304įleming HP,Fore SP, Goldblatt LA (1968) The formation of carbonyl compounds in cucumbers. Harwood Academic, Amsterdamĭrawert F, Heimann W, Enberger R, Tressl R (1965) Enzymatische verandrung des naturlichen apfelaromass bei der aurfarbeitung. O’Keeffe M (2000) Residue analysis in food: principles and applications. Gordon MH (1990) Principles and applications of gas chromatography in food analysis. Schomburg G (1990) Gas chromatography: a practical course. Rood D (1999) A practical guide to the care, maintenance, and troubleshooting of capillary gas chromatographic systems, 3rd edn. Niessen WMA (2001) Current practice of gas chromatography – mass spectrometry. James AT, Martin AJP (1952) Gas-liquid chromatography: the separation and microestimation of volatile fatty acids from formic acid to dodecanoic acid. New GC developments and applications will likely be related to multidimensional GC. The analyst must be knowledgeable about the characteristics of each of these GC components and understand basic chromatographic theory to balance the properties of resolution, capacity, speed, and sensitivity. The GC consists of a gas supply and regulators (pressure and flow control), injection port, column and column oven, detector, electronics, and a data recording and processing system. Some analytes can then be directly analyzed, while others must be derivatized prior to analysis to increase volatility or temperature stability. Sample preparation generally involves the isolation of solutes from foods, which may be accomplished by headspace analysis, distillation, preparative chromatography, or extraction. This chapter discusses details of GC sample preparation, hardware, columns, and chromatographic theory as it is uniquely applied to GC. The outstanding resolving properties of GC and the wide variety of detectors contribute to the sensitivity or selectivity in analysis. While the high selectivity of GC-ECD limits applications to a more limited array of compounds, it can be up to 1000 times more sensitive than GC-FID, thus being able to detect them in far lower concentrations.Gas chromatography (GC) has been used for the determination of a wide range of food components, but it is ideally suited to the analysis of thermally stable volatile substances. The flame ionization detector used in GC-FID analysis is considerably less selective than the ECD and can therefore be used to detect a wide variety of organic compounds. ![]() The observed drop can be used to determine which compounds are present, and in what concentrations. This creates a current, which is measured by the detector.ĭifferent chemical species will absorb the free electrons in different amounts, causing a drop in the current. The radioactive isotope releases electrons that collide with the makeup gas, causing more electrons to be released. The detector uses a radioactive beta particle emitter and a makeup gas. In GC-ECD analysis, a gas chromatography column separates the sample into its individual components, which are then passed through the electron capture detector. How does the electron capture detector work? This gives GC-ECD applications in environmental and food analysis, where it is used to screen samples for organochlorinated pesticides and highly hazardous polychlorinated biphenyl compounds (PCBs). GC-ECD can detect and measure electronegative chemical compounds, most notably halogens, organohalides, and nitrogen-containing compounds, with extremely high sensitivity.
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