Partial mass chromatogram

Figure 7. Partial mass chromatograms of the flash pyrolysate of the polar fraction of the Jurf ed Darawish-156 bitumen. Numbers indicate total number of carbon atoms.

Figure 12. Total ion chromatogram (a) and m/z 57 mass chromatogram (b) of the hydrocarbons obtained upon desulfurisation of the polar fraction of the Northern Apennines Marl bitumen. Numbers indicate total number of carbon atoms of n-alkanes. The inset in Figure 12b shows a partial mass chromatogram of m/z 113.

Figure 5. Partial mass chromatograms of m/z 308, showing the distribution of C20 isoprenoid thiophenes. Numbers refer to Figure 3.

Once the mass spectral information has been acquired, various software programs can be employed to print out a complete or partial spectrum, a raw or normalized spectrum, a total ion current (TIC) chromatogram, a mass chromatogram, accurate mass data, and metastable or MS/MS spectra. 

Fig. 1.6 Specific detection. Trace (a) shows a partial chromatogram for Arochlor 1254. Trace (b) shows the mass chromatogram for 292 characteristic of tetrachlorobiphenyls in the mixture. Trace (c) shows the mass chromatogram for 326 characteristic of pentachlorobiphenyls Source Own files... 

Figure 4. Partial TIC (black dots indicate alkylbenzenes, black squares indicate alkylpyrroles) and accurate (window 0.04 dalton) summed mass chromatograms of m/z 97.03 + 98.03 + 111.04 + 112.04 + 125.06 + 126.06 + 139.08 + 140.08 + 153.10 + 154.10 + 167.11 + 168.11 of flash pyrolysates of several high-molecular-weight fractions of Monterey-25. Peak numbers refer to Table I. Black and stippled peaks indicate alkylthiophenes with linear and isoprenoid carbon skeletons, respectively.

Figure 4. Mass chromatogram (m/e = 320) of grass and soil samples from Switzerland, analyzed for part-per-trillion (ppt) levels of TCDD. Inserted partial chromatograms show samples spiked with 20 ppt TCDD.

Figure 7. Gas chromatogram (FID) and partial mass spectra (GC-MS) of methyl chloride and methyl bromide in stored flour head gas...

Figure 6.12 Chromatography and mass spectrometry of plant waxes. (1) Thin-layer chromatogram of broccoli leaf wax and gas-liquid chromatogram of the hydrocarbon fraction isolated from this wax. (2) Partial gas-liquid chromatogram of the alkane fraction from the surface lipids of tobacco leaves. (3) Partial gas-liquid chromatograms of the hydrocarbons from N. muscorum illustrating resolution of 8- (a), 7- (b) and 6- (c) monomethyl heptadecanes on a 750ft capillary column. (A)-(C) Partial mass spectra taken at points indicated in (2) illustrating identification of n- and branched alkanes. Reproduced with permission from Kolattukudy (1980).

FIGURE 30.9 Partial m/z 191 and 205 mass chromatograms for fluid inclusions oils and crude oil, South Pepper-1, showing the distribution of hopanes and methylhopanes. Peak assignments define the stereochemistry at C-22 (S and R) a 3 and 3a denote 17a(H),2ip(H) and 17 3(H),21a(H)-hopanes, respectively.Ts = C2718a(H)-22,29,30-trisnorneohopane Tm = C2717a(H)-22,29,30-trisnorhopane = diahopane and 2a(Me) = methylhopane. Numbers in italics refer to the relative abundance of chromatograms (modified from Reference [34]). 

FIGURE 30.11 Partial added m/z 128.1 + 142.1 + 156.1 + 170.1 + 184.1 mass chromatogram of the fluid inclusion oil from Octavius-2 (3200 m) in the Vulcan Sub-basin, northern Australia, showing the distribution of alkyhiaphthalenes.The enlargements show details of the partial m/z 170.1 and 184.1 mass chromatograms over the indicated retention times. EN, ethylnaphthalene... 

FIGURE 30.12 Partial m/z 85 mass chromatogram of the Ludmilla-1 fluid inclusion oil, showing the distribution of n-alkanes, monomethylalkanes, and isoprenoids. Compound abbreviations n-alkane /-Cxx, isoprenoid MUD, methylundecanes MDD,... 

The chromatograms of the liquid phase show the presence of smaller and larger hydrocarbons than the parent one. Nevertheless, the main products are n-alkanes and 1-alkenes with a carbon number between 3 to 9 and an equimolar distribution is obtained. The product distribution can be explained by the F-S-S mechanism. Between the peaks of these hydrocarbons, it is possible to observe numerous smaller peaks. They have been identified by mass spectrometry as X-alkenes, dienes and also cyclic compounds (saturated, partially saturated and aromatic). These secondary products start to appear at 400 °C. Of course, their quantities increase at 425 °C. As these hydrocarbons are not seen for the lower temperature, it is possible to imagine that they are secondary reaction products. The analysis of the gaseous phase shows the presence of hydrogen, light alkanes and 1-alkenes. 

As early GC peaks elute in a few seconds or less, rapid scanning of the mass range of interest is necessary. Fast scanning also allows partially resolved GC peaks to be sampled several times,peak slicing, to facilitate identification of the individual components (Figure 12.5) provided that the dead volume of the interface is small compared to peak volumes. For the speedy interpretation of spectral data from complex chromatograms a... 

Presented in Figures la and 2a are reconstructed partial total ion current chromatograms obtained by the CGC/MS/DA run on the May, 1985 samples. Figures lb and 2b show mass spectra taken at a certain specified time and peak number. Figure lb shows the mass spectrum of phthalate plasticizer in the soil... 

Figure 1. Methylation linkage analysis of PSL-I by GC/MS total ion chromatogram of partially methylated alditol and myoinositol acetates (PMAA) from PSL-I carboxyl-reduced trisaccharide by gas chromatography /mass spectrometry in...

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