Typical gas chromatogram

When large numbers of chromatograms are analyzed visually from chart paper or tabular data, it is difficult to detect minor (or perhaps major) significant differences that may be present in samples from different locations or differences that could be attributed to changing physiochemical processes. A typical gas chromatogram of a PCB mixture (Figure 2) represents a 1 1 1 1 mixture of Aroclors 1242, 1248, 1254, and 1260. It contains more than 100 component peaks, of which 69 were selected for use in these analyses. 

Figure 1. Typical gas chromatograms of soil frcm an untreated garden (top) and sludge treated garden (bottcm). Conditions 15 m DB-5, 0.25 nm ID capillary colimn operated at 100 C (2 min) then programned at 10 C/min to 310 C (7 min hold).

Figure 10.2 shows a typical gas chromatogram of estriol isolated from urine and the standard estriol on the same column under the conditions just described. 

Figure G1.5.7 Typical gas chromatogram for cold-pressed orange oil. Reproduced with permission from Agilent Technologies, Inc. (see Internet Resources).

Pyrolysis of polystyrene produces an oil very high in concentration of the monomer, styrene and also other aromatic compounds. Eigure 11.15 shows a typical gas chromatogram for the pyrolysis oil produced from the pyrolysis of polystyrene, showing... 

Figure 14. Typical gas chromatogram of oxidation product. Key a,by solvent c, benzenedicarboxylic acid d, benzenemonohydroxydicarboxylic acid e, benzenetricarboxylic acid /, unknown g, benzenetetracarboxylic acid h, unknown i, benzenepentacarboxylic acid benzenehexacarbox-...

Figure 1. Typical gas chromatogram for a probe interacting with a polymer-coated stationary phase at temperature T. Retention volume -m x flow rate of carrier gas. (Reprinted with permission from ref. 3. Copyright 1982 Applied Science.)...

The first systematic investigation on the gas chromatographic separation of xanthine de-rivatives was published by Reisch and Walker. The naturally occurring xanthines, caffeine, theobromine and theophylline, as well as a number of derivatives, were gas chromatographed on an 1.5 % packed SE-30 column on Chromosorb W. In Table 20.1 the compounds are given and and in Figure 20.1 typical gas chromatograms. 

Figure 8. A typical gas chromatogram of pyrolysate of Whitby Formation kerogen. Identifications are...

The harvest of information about a mixture that can be reaped from the interpretation of a chromatogram is illustrated with reference to a typical gas chromatogram shown in Figure 13.11. 

Typical gas chromatogram of the degradation products evolved from (a) flame-retarded (FR)-PBT, and (b) the mass chromatogram for miz 362 corresponding to the parent ion of SbBrs observed for FR-PBT along with the mass sp>ectrum of SbBrs, from Ref. 33. Column a metal capallary (Frontier Lab Ultra AUoy-1, 0.25 mm 1. D. x 15 m, 0.15 /an of immobilized PDMS) programmed from 35 to 300°C at 10°C/min. 

Figure 11.8 A typical gas chromatogram. (A), (B), (C). (D). and (E) are detector signals due to different sample components which emerge from the column at different times depending on their partition coejflcients.

Fig. 3.1 Typical gas chromatograms of two crude oils where each peak represents one (or more) individual compounds. The height (or area) of the peak is proportional to its concentration in the injected sample. The time taken for the substance to elute from the column, which is temperature programmed to speed up the analysis, is used to identify the substance. The presence and the ratio of the two branched hydrocarbons, pristane (2,6,10,14-tetramethylpentadecane) and phytane (2,6,10,14-tetramethylhexadecane), can be used to identify the source of the oil...

GC analysis. It is possible to perceive a stale flavor in stored beer that not only involves the cardboard flavor that was studied with a headspace analysis in a previous paper (5) but also an astringent, aldehydic and musty flavor in the odor concentrate. Figure 1 shows typical gas chromatograms of beer with and without storage at 3T C. The 132 peaks detected by GC were used as variables for the subsequent multivariate analysis (9). Table 1 shows the compounds identified in this study as 14 alcohols, 11 esters, 6 aldehydes, 4 ketones, 2-furfuryl ethyl ether, 2-acetylfuran, y -nonalactone, and 4 acids. 

A Hewlett-Packard 4890 Series II equipped with a capillary, non-polar PONA column (50m X 0.25mm id x 0.25pm) and a glass liner split injector was used for quantifying purposes. Plate 26 indicates a typical gas chromatogram obtained of the reaction product after formylation. The following set points were used ... 

For example, a high-resolution capillary column gas chromatograph (GC) can be used to separate five volatile alkyllead compounds, with temperature programming from 40 to 180°C. An interface using a heated transfer line was used to couple the GC to the ICP-MS. A typical gas chromatogram showing the ion current for lead plotted as a function of time (eluent volume) for the compounds tetramethyllead, trimethylethyllead, dimethyldiethyllead, methyltriethyllead, and tetraethyllead is shown in Figure 5.5. 

---