Gas-liquid chromatography columns, capillary

Douse JMF. 1981. Trace analysis of explosives at the low picogram level by silica capillary column gas-liquid chromatography with electron-capture detection. J Chromatogr 208 83-88. 

Aromatic Fraction from Engine Oils Obtained by Capillary Column Gas-Liquid Chromatography and Nitrogen-Selective Detection, Anal. Chem. (1975) 47, 540. 

T3. Tanida, N., Hisaka, Y., and Shimoyama, T., Evaluation of polyethylene glycol-HT as a stationary phase for capillary column gas-liquid chromatography of trimethylsilyl ethers ofbile add methyl esters. J. Chromatogr. 240, 75-79 (1982). 

S Bjorkman, et al. Determination of alfentanil in serum by radioimmunoassay or capillary column gas liquid chromatography—A comparison of the assays. Acta Pharm Nord 1 211, 1989. 

Desethylated Metabolites in Plasma by Capillary Column Gas-Liquid Chromatography... 

The purity of 1 and 2 is assessed by analytical gas-liquid chromatography (GC) on a Hewlett-Packard 5890 gas chromatograph equipped with a flame-ionization detector and fitted with a 50 m x 0.2 mm HP-5 fused silica glass capillary column using linear temperature programming from an initial temperature of 150°C for 5 min to a final temperature of 200°C for 10 min at a rate of 5°C/min. 

Hewlett-Packard Model 6890 equipped with a nitrogen-phosphorus flame ionization detector Capillary column for gas-liquid chromatography (GLC), DB-1, 0.53-mm i.d. x 15 m, l-pm film thickness (J W Scientific)... 

The extracted fractions were esterified with either BF3-MeOH reagent or diazomethane and analyzed by GLC. Gas liquid chromatography (GLC) was conducted with a Perkin-Elmer Sigma 3 equipped with flame ionization detector. Separations were obtained on a Hewlett Packard 12 m x 0.2 mm i.d. capillary column coated with methyl silicon fluid (OV-101). The temperature was maintained at 80°C for 2 min then programmed from 80 to 220°C at 8°C/min. The injector temperature was 250°C. Mass spectra were obtained on a Hewlett Packard model 5995 GC-MS mass spectrometer, equipped with a 15 m fused silica capillary column coated with 5% phenyl methyl silicone fluid. Spectra were obtained for major peaks in the sample and compared with a library of spectra of authentic compounds. 

Analysis Techniques. The contents of the major breakdown products of xetralin (naphthalene and 1-methyl indan) present in the distillate were determined by gas-liquid chromatography using a Hewlett Packard Series 5750 Research Chromatograph with a 62m x 0.5mm diameter glass capillary SCOT column coated with nonpolar SE 30 liquid phase (see Reference (4 ) for details). 

The reaction products were analyzed on-line by gas liquid chromatography (Varian 3400) on a 50 m CPSil-5 capillary column from Chrompack, hydrogen being the carrier gas (15 psi), with a temperature programming from 45 to 170°C (5°C.min 1) then from 170 to 180°C (2°C.mm1). 

Ho JS, Tang PH, Eichelberger JW, et al. 1993. Determination of organic compounds in water by liquid solid extraction followed by supercritical fluid elution and capillary column gas chromatography/mass spectrometry. Denver, CO American Chemical Society, 313-315. 

Gas-Liquid Chromatography. In gas-liquid chromatography (GLC) the stationary phase is a liquid. GLC capillary columns are coated internally with a liquid (WCOT columns) stationary phase. As discussed above, in GC the interaction of the sample molecules with the mobile phase is very weak. Therefore, the primary means of creating differential adsorption is through the choice of the particular liquid stationary phase to be used. The basic principle is that analytes selectively interact with stationary phases of similar chemical nature. For example, a mixture of nonpolar components of the same chemical type, such as hydrocarbons in most petroleum fractions, often separates well on a column with a nonpolar stationary phase, while samples with polar or polarizable compounds often resolve well on the more polar and/or polarizable stationary phases. Reference 7 is a metabolomics example of capillary GC-MS. 

Derivatives of amino acids (Table 9.10) are required because amino acids are not themselves sufficiently volatile for gas-liquid chromatography and difficulties may be encountered in the choice and method of derivatization. In the past no single column was normally capable of resolving the derivatives of such a diverse group of compounds but the introduction of fused silica capillary columns has resulted in considerably improved resolution. 

Alexander, G., and Rutten, G.A.F.M., Surface characteristics of treated glasses for the preparation of glass capillary columns in gas-liquid chromatography, /. Chromatogr., 99, 81-101, 1974. 

The picolinyl esters (32) permit the location of double bonds, since these give distinctive fragmentations that are characteristic of the double-bond positions. They are easily prepared and are not too polar for separation by gas-liquid chromatography (GLC). It has been confirmed that the picolinyl esters are the most useful, since they permit unequivocal identifications even with polyunsatured components. It was also demonstrated that derivatives of this type, prepared from natural mixtures, give satisfactory resolutions when subjected to GLC on capillary columns of fused silica coated with a nonpolar methylsilicone phase, for identification by mass spectrometry (MS). 

To improve the separation of the derivatives of fatty acids with the same effective carbon number, e.g., palmitoleic (C16 1), linoleic (18 2), andmyristic (C14 0), Baty et al. (33) reported the preparation of the anthrylmethyl esters derivatives of several fatty acids (with 9-hydroxy-methylanthracene and the catalyst 2-bromo-l-methylpyridinium iodide (BMPI)) with a view to analysis by HPLC and LC-MS (with gradient elution on a ZORBAK 5-/zm Cl8 column) (see Chemical Structure 1). The excess reagents were evaporated under nitrogen at 50°C, and the de-rivatized acids were taken up in 1 ml of mobile phase prior to chromatography. This method did not allow the resolution of the C16 1, 08 2, and C14 0 esters, although HPLC data obtained for the other acids correlated well with that obtained by capillary gas-liquid chromatography. 

Since Pasteur separated crystalline sodium ammonium tartrate manually in 1848, many researchers have worked on the subject of enantiomeric separation. In 1939 Henderson and Rule fully separated derivatives of camphor by column chromatography using lactose as a stationary phase material [1]. Gil-Av et al. [2] were able to separate amino acid derivatives on a polysiloxane-based stationary phase by gas chromatography (GC) in 1966. Since then many approaches for a successful distinction between enantiomers have been developed for capillary GC and liquid chromatography [3]. It is still a current topic for researchers searching for chiral separation with SciFinder [4] results in 812 hits and searching for chiral recognition leads to 285 hits for the year 2003 only. 

Grushka, E. and Solsky, J.F., p-Azoxyanisole liquid crystal as a stationary phase for capillary column gas chromatography, Anal. Chem., 45, 1836, 1973. 

Figures 4a—c. Capillary column gas chromatograms of the aromatic hydrocarbon fraction of selected samples from the Nordlinger Ries. M+ = molecular ion, BP = base peak in the corresponding mass spectra. The sample from 151.5 m of well NR-10 contains steroid olefins due to incomplete liquid chromatography separation.

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