Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Gas chromatography-mass spectrometry instrumentation

The IRIS spectra of Titan s atmosphere returned from Voyager I show extensive organic composition across the entire disc of Titan (Figure 10.7) and only promises (or threatens) more organic complexity when the measurements from the gas chromatography/mass spectrometry instruments on the Huygens probe are returned. [Pg.297]

It is clear that a complex hydrocarbon polymer chemistry must exist in the atmosphere of Titan involving polyyne species, polynitrile species and mixtures of the two, and additional routes to polyaromatic hydrocarbon formation. This presents a significant problem for the gas chromatography/mass spectrometry instruments on the Huygens probe. There should be hydrocarbon fragments, producing perhaps... [Pg.300]

Christman et al. [72] gave details of procedures for extraction, clean-up, and concentration of samples of soil prior to the determination of their content of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans by gas chromatography and by gas chromatography-mass spectrometry. Instrumental parameters are also included. Some typical results are tabulated. [Pg.178]

Early studies of bile acid mass spectra were made by Bergstrom, Ryhage, and Stenhagen (3-5) and the results were used to determine the structure of Hammarsten s a-phocaecholic acid (6). Other groups applied mass spectrometry to the elucidation of structures of the closely related bile alcohols (7). At about this time combined gas chromatography-mass spectrometry instruments were developed that could be used in studies of compounds with molecular weights as high as those of bile acid derivatives (8-13). The early... [Pg.209]

Gas chromatography/mass spectrometry (GC/MS) is the synergistic combination of two powerful analytic techniques. The gas chromatograph separates the components of a mixture in time, and the mass spectrometer provides information that aids in the structural identification of each component. The gas chromatograph, the mass spectrometer, and the interface linking these two instruments are described in this chapter. [Pg.199]

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],... [Pg.32]

As an example of the application of gas chromatography-mass spectrometry, Fig. 1.7 shows a reconstructed chromatograph obtained for an industrial sludge. The Finnigan MAT 1020 instrument was used in this work. Of the 27 compounds searched for, 15 were found. These data were automatically quantified. This portion of the report contains the date and time at which the run was made, the sample description, who submitted the sample and the analyst, followed by the names of the compounds. If no match for a library entry was found, the component was listed as not found . Also shown is the method of quantification and the area of the peak (height could also have been chosen). [Pg.79]

FSIS laboratories also use chemical techniques and instrumentation to identify select antibiotic residues. The tetracyclines of interest are identified by thin layer chromatography. Sulfonamides are detected and quantified by fluorescence thin lay chromatography and confirmed by gas chromatography/mass spectrometry. Amoxicillin and gentamycin are identified and/or quantified by high pressure liquid chromatography. Similar techniques are used to identify ionophores and other antimicrobials of interest. [Pg.141]

The next three chapters deal with the latest techniques for the analysis of organic pollutants in wastewaters and drinking waters. Instrumental analyses using liquid chromatography and gas chromatography/ mass spectrometry (GC/MS) are described. Suitable sampling techniques for these pollutants are emphasized for subsequent instrumental analyses and bioassays. [Pg.1]

Preliminary structural characterization was carried out on the soluble products of treatment with BF3/CH3OH (or LiAlH (8), in order to verify the similarity of our samples to materials studied previously (8-11). Gas chromatography-mass spectrometry (GC-MS) (Finnigan 3300 spectrometer) was used to establish the molecular ion and fragmentation patterns solution-state 13C NMR (IBM Instruments WP-200 spectrometer) was employed for quantitation of CH2, CH2OH, and CHOH moieties. [Pg.216]

Steinberg, R, and Fox, A. (1999), Automated derivatization instrument Preparation of alditol acetates for analysis of bacterial carbohydrates using gas chromatography-mass spectrometry, Anal. Chem.,11,1914-1917. [Pg.541]

In the absence of tandem mass spectrometry equipment, almost equally reliable estimations of the PA concentrations can be made using gas chromatography-mass spectrometry (GC-MS). A standard quadrupole instrument, such as the one used for organic acid analysis, will be sufficient. Depending on the derivative, a choice between positive and negative ionization will have to be made. In general, a more extensive prepurification of the biological samples, will have to be realized. [Pg.133]

Ranid instrumental techniques were used to elucidate off-flavor problems in raw and processed rice products, raw and roasted peanuts, and corn-soy food blends. Less than a gram of the solid material was secured in a standard or special injection port liner of the gas chromatograph. Then, the volatiles from the sample were steam distilled in situ and identified by combined gas chromatography/mass spectrometry. [Pg.48]

Gas Chromatography-Mass Spectrometry. A Finnigan 4500/Incos instrument with a 30-m X 0.32-mm i.d. capillary column coated with SP-B-5 was used. The GC parameters were as follows injector, 270 °C column oven temperature programmed, 50 °C (0.1 min, hold) 15 °C/min to 100 °C, 5 °C/min to 270 °C internal standard, anthracene-djo helium flow, 3.0 mL/min sample size, 3.0 /xL. MS conditions were as follows El, 70 eV scan (m/z), 35-650 daltons source temperature, 250 °C filament current, 0.5 A sensitivity, 10-8 A/V. (NOTE When the name of a compound is followed by (confirmed) , it means that the standard material was analyzed for confirmation under conditions identical to those of the sample when the name is followed by (tentative) , it means that the mass fragmentography showed the best fit (>80 ) based on the National Bureau of Standards [NBS] library computer search.)... [Pg.171]

Traditionally HPLC methods were used for isoflavone analysis from foods [Wang et al., 1990], and gas chromatography/mass spectrometry (GC/MS) to determine isoflavones and their metabolites in human biological fluids including urine [Adlercreutz et al., 1991 Kelly et al., 1993], plasma [Adlercreutz et al., 1993], and feces [Adlercreutz et al., 1995 Kurzer et al., 1995]. HPLC with photodiode array (PDA) detection was introduced in 1994 to measure these analytes in human urine [Franke and Custer, 1994 Xu et al., 1994]. Compared to GC/MS, HPLC methods require fewer steps for sample preparation and analysis and demand less technician time and less expensive instrumentation. [Pg.225]

It may not be possible to detect GHB and related compounds with common urine or serum (body fluid) tests. In cases where an unused portion of the drug cannot be recovered, gas chromatography-mass spectrometry (a high-technology instrument that separates a chemical mixture and identifies its composition) can be used to detect GHB and related compounds from a sample of serum, plasma, blood, or urine. [Pg.216]


See other pages where Gas chromatography-mass spectrometry instrumentation is mentioned: [Pg.149]    [Pg.42]    [Pg.167]    [Pg.209]    [Pg.210]    [Pg.346]    [Pg.374]    [Pg.149]    [Pg.42]    [Pg.167]    [Pg.209]    [Pg.210]    [Pg.346]    [Pg.374]    [Pg.106]    [Pg.1032]    [Pg.370]    [Pg.25]    [Pg.343]    [Pg.502]    [Pg.1250]    [Pg.47]    [Pg.720]    [Pg.72]    [Pg.78]    [Pg.173]    [Pg.207]    [Pg.72]    [Pg.113]    [Pg.78]    [Pg.1250]    [Pg.10]    [Pg.75]    [Pg.534]    [Pg.36]    [Pg.46]    [Pg.1032]    [Pg.254]    [Pg.278]    [Pg.106]   
See also in sourсe #XX -- [ Pg.275 ]

See also in sourсe #XX -- [ Pg.155 ]




SEARCH



Chromatography instrumentation

Gas chromatography instrumentation

Gas chromatography instruments

Gas chromatography/mass spectrometry

Gas mass spectrometry

Instrumental Chromatography

Instruments chromatography

Mass spectrometry instrument

Mass spectrometry instrumentation

Spectrometry instrumentation

© 2024 chempedia.info