Gas chromatography-mass spectrometry coupling

S Komatsu, S Murata, H Aoyama, T Zenki, N Ozawa, M Tateishi, JJ Vrbanac. Micro-quantitative determination of ciprostene in plasma by gas chromatography-mass spectrometry coupled with an antibody extraction. J Chromatogr 568 460, 1991. 

Richmond, R. Pombo-VDlar E. (1997). Gas chromatography-mass spectrometry coupled with pseudo-Sadtler retention indices, for the identification of components in the essential oD of Curcuma longa L. Journal of Chromatography A, Vol.760, No.2, Qanuary 1997), pp. 303-308, ISSN 0021-%73... 

JalaU-Heravi, M. and Vosough, M., Characterization and determination of fatty acids in fish oil using gas chromatography-mass spectrometry coupled with chemometric resolution techniques. J. Chromatogr. A, 1024, 165-176 (2004). 

Wet granulation and direct compression are two methods used to manufacture tablets in the pharmaceutical industry. Zomer et al. used pyrolysis-gas chromatography-mass-spectrometry coupled with SVM classification to discriminate between the two tablet production methods.Mass spectra data were submitted to a PCA analysis, and the first principal components were used as input for SVM models having linear, polynomial, and Gaussian RBF kernels. SVM classifiers with polynomial and RBF kernels performed better in prediction than discriminant analysis. 

H. J. Goites, B. M. Bell, G. D. Pfeiffer and J. D. Graham, Multidimensional chromatography using on-line coupled microcolumn size exclusion cliromatography-capillary gas chromatography-mass spectrometry for determination of polymer additives , J. Microcolumn Sep. 1 278-288. (1989)... 

The data in Table I are also significant in terms of the type of analysis to determine the presence of NDMA. In all cases analysis was done using gas chromatography coupled with a Thermal Energy Analyzer, a sensitive, relatively specific nitrosamine detector (12). Further, in six of the studies, the presence of NDMA in several samples was confirmed by gas chromatography-mass spectrometry (GC-MS). The mass spectral data firmly established the presence of NDMA in the beer samples. 

Of the methods developed for the identification of hydrocarbon mixtures, only coupled gas chromatography-mass spectrometry holds any real promise of certain identification and this only at a prohibitive cost in time spent characterising minor peaks. It would be far more efficient to develop rapid screening procedures which would eliminate all but a few possibilities, and then use gas chromatography-mass spectrometry to isolate and identify a few key peaks to confirm the characterisation. This is precisely the scheme adopted independently by a number of laboratories. 

Smith [83] classified large sets of hydrocarbon oil infrared spectral data by computer into correlation sets for individual classes of compounds. The correlation sets were then used to determine the class to which an unknown compound belongs from its mass spectral parameters. A correlation set is constructed by use of an ion-source summation, in which a low resolution mass spectrum is expressed as a set of numbers representing the contribution to the total ionisation of each of 14 ion series. The technique is particularly valuable in the examination of results from coupled gas chromatography-mass spectrometry of complex organic mixtures. 

An analysis performed by gas chromatography can usually also be performed by coupled gas chromatography-mass spectrometry, often with some increase in sensitivity, and with considerably greater certainty in the identification of the compounds. This technique has been applied to seawater [415] and to marine sediments [416]. 

To examine variation in the quality of methyl ketones expressed by females and newly-emerged males, we determined the number of unique methyl ketones expressed by individual snakes and compared the relative concentrations of individual methyl ketones comprising the overall pheromone profiles for the two groups. The methyl ketones present in the pheromone extracts were identified by gas chromatography / mass spectrometry (Hewlett Packard 5890 Series II gas chromatograph coupled with a Hewlett Packard 5971 Series mass selective detector— see LeMaster and Mason 2003 for full description of the GC/MS platform and methods). 

Colostrum or AG-secretions of three different women were separately mixed with Florisil (Merck 1 3 w/w). This material (6 samples) was transferred to a small column that already contained about the same amount of Florisil and enough methylene chloride to cover the two Florisil-batches. Subsequently, organic components adsorbed on the Florisil were eluted with solvents of increasing polarities (hexane to methanol). The fractions were concentrated and analysed by coupled gas chromatography/mass spectrometry (Francke 1988). 

Once into the 21st century, hyphenated instrumentation (i.e., those that couple two instruments together) became prevalent in laboratories. This is the combination of two or more, often different, instruments. In simple terms, the purpose is to first separate the analyte of interest and then to identify it. This takes place using a sample injected into the combined instruments. The most common of the hyphenated instruments is the gas chromatograph, the output of which is fed into a mass spectrometer to produce a gas chromatography-mass spectrometry (GC-MS) [35],... 

Solid-phase microextraction has also been used for to determine volatile organic compounds in soil [26]. Target compounds were adsorbed directly from a head-space sample above a soil layer onto a fused-silica fibre. Vacuum distillation coupled with gas chromatography-mass spectrometry [27], head-... 

We discussed the fundamentals of mass spectrometry in Chapter 10 and infrared spectrometry in Chapter 8. The quadrupole mass spectrometer and the Fourier transform infrared spectrometer have been adapted to and used with GC equipment as detectors with great success. Gas chromatography-mass spectrometry (GC-MS) and gas chromatography-infrared spectrometry (GC-IR) are very powerful tools for qualitative analysis in GC because not only do they give retention time information, but, due to their inherent speed, they are also able to measure and record the mass spectrum or infrared (IR) spectrum of the individual sample components as they elute from the GC column. It is like taking a photograph of each component as it elutes. See Figure 12.14. Coupled with the computer banks of mass and IR spectra, a component s identity is an easy chore for such a detector. It seems the only real... 

NMR) [24], and Fourier transform-infrared (FT-IR) spectroscopy [25] are commonly applied methods. Analysis using mass spectrometric (MS) techniques has been achieved with gas chromatography-mass spectrometry (GC-MS), with chemical ionisation (Cl) often more informative than conventional electron impact (El) ionisation [26]. For the qualitative and quantitative characterisation of silicone polyether copolymers in particular, SEC, NMR, and FT-IR have also been demonstrated as useful and informative methods [22] and the application of high-temperature GC and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) is also described [5]. 

Samples were extracted with n-hexane, dried over sodium sulfate and stored at 20 °C until analysed by coupled gas chromatography-mass spectrometry (GC-MS). 

Reusser, D.E. and Field, J.A. Determination of benzylsuccinic acid in gasoline-contaminated groundwater by solid-phase extraction coupled with gas chromatography-mass spectrometry. J. Chromatogr. A, 953(l-2) 215-225. 2002. 

We first confirmed the formation of these macrocycles in the polymerization of THF by using coupled gas chromatography/mass spectrometry ( 2). Macrocyclic ethers containing up to 8 THF units could be separated and identified by this method (23). The two predominant macrocyclic species found in THF polymerization mixtures are a cyclic tetramer and a cyclic pentamer. In analogy to the "crown ether" nomenclature, we proposed the name 20-crown-4 for the cyclic tetramer and 25-crown-5 for the cyclic pentamer (22). 

Coupling of Proton-Transfer-Reaction Mass Spectrometry with Gas Chromatography-Mass Spectrometry... 

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