Gas chromatography/mass spectrometry data

Dixon, S.J., Brereton, R.G, Soini, H.A., Novotny, M.V. and Penn, D.J. (2007) An automated method for peak detection and matching in large gas chromatography-mass spectrometry data sets. Journal of Chemometrics In press. 

The Chem Master Workstation is a gas chromatography and gas chromatography-mass spectrometry data-processing system that speeds the flow of data through the laboratory and provides essential quality-assurance and quality-control review. It is a PC-based integrated hardware/ software system that converts gas chromatographic and gas chromatography-mass spectrometric data into reliable analytical reports. 

Gas Chromatography/Mass Spectrometry Data Package Content... 

Gas chromatography - mass spectrometry data of the "aromatic hydrocarbon" fractions of nearly 100 Deep Sea Drilling Project (DSDP) and Ocean Drilling Program (ODP) sediment samples have been re-examined for the occurrence of organic sulfur compounds (OSC). Approximately 70% of the samples contain OSC with varying distribution patterns, although isoprenoid thiophenes are invariably present. 

SpectConnect Massachusetts Institute of Technology Systematic identification of conserved metabolites in gas chromatography/mass spectrometry data for metabolomics (http //spectconnect.mit.edu/)... 

S.E. Stein, An integrated method for spectrum extraction and compound identification from gas chromatography/mass spectrometry data, J. Am. Soc. Mass Spectrom., 10, 770-781 (1999). 

Stein, S.E. An Integrated Method for Spectrum Extraction and Compound Identification from Gas Chromatography/Mass Spectrometry Data, J. Am. Soc. Mass Spectrom. 10(8), 770-781(1999). 

Mazurek, M. A., Cass, G. R., and Simoneit, B. R. T. (1989) Interpretation of high resolution gas chromatography and high resolution gas chromatography/mass spectrometry data acquired from atmospheric organic aerosol samples. Aerosol Sci. Technoi, 10, 408-420. 

Zhang, L-x. Yun, Y-f. Liang, Y-z. Cao, D-s. (2010). Discovery of mass spectral characteristics and automatic identification of wax esters from gas chromatography mass spectrometry data. Journal of Chromatography A, Vol.1217, No.23, 0une 2010),... 

W. Eckel and T. Kind. Use of boiling point - Lee retention index correlation for rapid review of gas chromatography - mass spectrometry data. Anal. Chim. Acta, 494(l-2) 235-243, 2003. 

Xu, Z., Sun, X. and Harrington Pde, B. (2011) Baseline correction method using an orthogonal basis for gas chromatography/mass spectrometry data. Anal. Chem. 83, 7464—7471. 

New techniques such as Py/GC/MS/DS (pyrolysis/gas chromatography/mass spectrometry-data system) and Py/MS/DS have been applied for detection and structural elucidation of complex organic compounds. 

Dromey, R.G., Stefik, M. J., Rindfleisch, T.C. and Duffield, A.M. (1976), Extraction of mass spectra free of background and neighbouring component contributions from gas chromatography/mass spectrometry data. Anal. Chem., 48,1368. 

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. 

P.J. Dunlop, C.M. Bignell, J.F. Jackson, D.B. Hibbert, Chemometric analysis of gas chromatographic data of oils from Eucalyptus species. Chemom. Intell. Lab. Systems 30 (1995) 59-67. K. Varmuza, F. Stangl, H. Lohninger and W. Werther, Automatic recognition of substance classes from data obtained by gas chromatography, mass spectrometry. Lab. Automation Inf. Manage., 31 (1996) 221-224. 

When pushed to the limit by overriding human health concerns, residue chemists have achieved detection limits of Ippt (Ingkg ) or even into the low ppqr (1 pg kg ) range. An example at the 1 ppt level is provided by methods for 2,3,7,8-tetrachlorodibenzodioxin (TCDD) in milk and TCDD in adipose tissue. Eor relatively clean matrices such as water and air, preconcentration on solid-phase adsorbents followed by GC or gas chromatography/mass spectrometry (GC/MS) can provide detection limits of 1 ng m and less for air (examples in Majewski and Capel ) and 1 ngL and less for water (examples in Larson et A summary of units of weight and concentration used to express residue data is given in Table 1. 

Scientists need to classify and organize complex data, such as that yielded by medical tests or analysis via GC-MS (gas chromatography-mass spectrometry). The data may be multifaceted and difficult to interpret, as different tests may conflict or yield inconclusive results. Growing cell structures may be used to assess medical data for example, such as that obtained from patient biopsies, and determine whether the test results are consistent with a diagnosis of breast cancer.1... 

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. 

Pyrolysis-Gas Chromatography-Mass Spectrometry. In the experiments, about 2 mg of sample was pyrolyzed at 900°C in flowing helium using a Chemical Data System (CDS) Platinum Coil Pyrolysis Probe controlled by a CDS Model 122 Pyroprobe in normal mode. Products were separated on a 12 meter fused capillary column with a cross-linked poly (dimethylsilicone) stationary phase. The GC column was temperature programmed from -50 to 300°C. Individual compounds were identified with a Hewlett Packard (HP) Model 5995C low resolution quadruple GC/MS System. Data acquisition and reduction were performed on the HP 100 E-series computer running revision E RTE-6/VM software. 

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). 

Figure 2.2 shows the total ion current trace and a number of appropriate mass chromatograms obtained from the pyrolysis gas chromatography-mass spectrometry analysis of the polluted soil sample. The upper trace represents a part of the total ion current magnified eight times. The peak numbers correspond with the numbers mentioned in Table 2.1 and refer to the identified compounds. The identification was based on manual comparison of mass spectra and relative gas chromatographic retention times with literature data [34, 35] and with data of standards available. In some cases unknown compounds were tentatively identified on the basis of a priori interpretation of their mass spectra (labelled tentative in Table 2.1). 

In a subsequent study, Schnitzer and Spiteller [15] hydrolyzed each fraction with 2 M H2S04. After neutralization of the soluble materials, the latter were reduced with NaBH4 and then acetylated. The resulting acetates were analyzed by capillary gas chromatography/mass spectrometry, and identified by comparing their mass spectra with those of reference compounds of known structures and with literature data. Eighteen N-heterocyclics were identified. These compounds induded hydroxy-and oxy-indoles, quinolines, isoquinolines, aminobenzofurans, piperidines, pyrro-lines, and pyrrolidines. In addition, a number of benzylamines and nitriles were also identified. It is noteworthy that the N heterocyclics were isolated and identified without the use of pyrolysis. 

In the following discussion, three types of air pollutant analytical data will be examined using principal component analysis and the K-Nearest Neighbor (KNN) procedure. A set of Interlaboratory comparison data from X-ray emission trace element analysis, data from a comparison of two methods for determining lead In gasoline, and results from gas chromatography/mass spectrometry analysis for volatile organic compounds In ambient air will be used as Illustrations. 

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