Gas chromatograph-mass GC-MS

GC-EID Gas chromatograph, flame ionization detector GC-MS Gas chromatograph, mass spectroscopy... 

Gas chromatography/mass spectrometry (GC/MS) Gas chromatograph equipped with a split/splitless injector, autosampler, DB-5 MS fused-silica column, 15 m x 0.25-mm i.d., 0.25-qm film thickness and mass-selective detector... 

Chromatographic methods are also often used as part of systems that are called hyphenated methods, (see Chapter 15) where the output of the chromatographic section is used as the input for an identification method such as mass spectrometry. These hyphenated methods are also most often referred to by their acronyms, for example, GC-MS—gas chromatography-mass spectrometry and HPLC-MS—high-performance liquid chromatography-mass spectrometry. Note that although ultraviolet-visible (UV-Vis) is hyphenated, it is not a hyphenated method in that it does not consist of two different methods of analysis. Hyphenated methods will be discussed fully in Chapter 15. 

The liquid products were quantified by GC-FID (gas chromatograph with flame ionisation detector) and characterised with GC-MS (gas chromatograph with mass spectrometer). The aromatics content was monitored on-line with a near infrared spectrometer that was calibrated by proton nuclear magnetic resonance spectrometry. 

FTIR Fourier transform infrared spectroscopy (technique useful in identifying and analyzing various unknown compounds, such as environmental pollutants) GC Gas chromatography (most commonly used analytical technique for organics) GC/MS Gas chromatography/mass spectrometry (technique based on chromatographic separation, followed by chemical or electron-impact ionization and identification of the mass spectra of the ionized fragments)... 

All samples were extraeted with diehloromethane in an automatic extractor (Biichi B-811). Surrogate recovery standards (D8-naphthalene, DlO-phenanthrene, D12-perylene) were spiked on each PUF and QFF prior to extraction. The volume was reduced after extraction under a gentle nitrogen stream at ambient temperature, and fractionation achieved on a silica gel column. Samples were analyzed using a GC-MS (gas chromatograph coupled with a mass spectrometer) HP 5975 with a J W Scientihc fused silica column DB-5MS, 5% Ph for PAHs. Terphenyl was used as an internal standard. Detection and quantification limits were controlled by laboratory and field blanks, are site dependent and were reported elsewhere (Lammel et al. 2009b). 

GC-MS Gas chromatography-mass spectrometry. An analytical procednre that combines a gas chromatograph, which separates mixtures of componnds into individnal components, with a mass spectrometer, which breaks the compounds into fragments that indicate the molecular weight and structure of each component. This procedure is one of few that can provide reliable identifications of organic compounds. 

W whole (unfiltered) water sample P particulate phase D dissolved + colloidal phase. LLE liquid - liquid extraction F - SPE filtration - solid phase extraction F filtration GC-MS gas chromatography - mass spectrometry GC - FH) gas chromatography - flame ionization detection HPLC - FI high perfomance liquid chromatograph - fluorescence spectrophotometry C18 - FI Cl8 column chromatography - fluorescence spectrophotometry. 

Some detectors can give additional information about the elutes (the eluted solutes). One example is the gas chromatograph—mass spectrometer (GC-MS), which produces a mass spectrum of each compound as well as its mass and location in the chromatogram. This powerful means of detection can be used when standard samples are not available to help determine the identities of the solutes. A beam of ions bombards each compound as it emerges from the chromatograph. The compound breaks up into ions of different masses, providing a spread of narrow peaks instead of one peak for each compound. The relative amount of each fragment is determined and used to help identify the compound. 

A chemist treats toluene (methylbenzene) with chlorine in the presence of a metal catalyst. A sample of the reaction mixture is injected into a GC-MS unit (gas chromatograph-mass spectrometer). One of the compounds that is separated... 

The GAGI samplers, installed along traverses at both Honerat and Unknown, were left in place for 5 months before being retrieved. Retrieved samplers from both locations were sent to Gore Laboratories where they were heated, and compounds were thermally desorbed and analyzed with a gas chromatograph/mass spectrometer (GC/MS). 

GCMS-QP 2000 gas chromatograph mass spectrometer, GCMS-Q 1000 and GC-QP 1000A gas chromatograph mass spectrometer Mispack 200 GCMS QP series MS data system... 

Mass-spectral (MS) Analysis. Mass spectral analyses were obtained using a computerized Finnigan Model 1015 gas chromatograph-mass spectrometer (GC-MS) operated at 70 eV. Samples were introduced via direct insertion probe or by utilizing the GC-MS combination, both operated over a programmed temperature range. 

In addition, most of these aqueous phase experiments included product identification using gas chromatographic-mass spectrometric (GC-MS) or liquid chromatographic-MS techniques. Product analyses were used to verify that disappearance kinetics were indeed due to hydrolysis reactions. 

Gas chromatographic-mass spectrometric (GC-MS) calibration standard mixes for quantitation were prepared in ethyl ether at concentrations of 20, 50, and 75 ppm. Internal standard spiking solution containing 1-chlorohexane, 1-chlorododecane, and 1-chlorooctadecane was prepared from individual stock solutions in methanol of each component. Two hundred microliters of each solution were added to ethyl ether and diluted to 2 mL. Forty microliters of this internal standard mix was added to the column extracts before diluting to 2 mL to yield a final concentration of 100 ppm per internal standard component. 

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