Gas-liquid chromatography/mass

The structures of many oligosaccharide chains can be elucidated by gas-liquid chromatography, mass spectrometry, and high-resolution NMR spectrometry. Glycosidases hydrolyze specific linkages in oligosaccharides and are used to explore both the structures and functions of glycoproteins. 

Defaye, K. and Garcia Fernandez, J.M., Protonic and thermal activation of sucrose an the oligosaccaride composition of caramel. Carbohydrate Res., 256, Cl, 1994. Ratsimba, V. et al.. Qualitative and qnantitative evaluation of mono- and disaccharides in D-fructose, D-glucose and sucrose caramels by gas-liquid chromatography-mass spectrometry di-D-fructose dianhydrides as tracers of caramel authenticity, J. Chro-matogr. A, 844, 283, 1999. 

J. N. Damico and R. P. Barron. Application of Field Ionization to Gas-Liquid Chromatography-Mass Spectrometry (GLC-MS) Studies. Anal. Chem., 43(1971) 17-21. 

R.E. Sawicki, E. and Krost, K./ Estimation of N-nitroso-dimethylamine Levels in Ambient Air by Capillary Gas-Liquid Chromatography/ Mass Spectrometry, Anal. Lett. 1976, 9(6) 579-594. 

Alme B, Bremmelgaard A, Siovall J, Thomassen P (1977) Analysis of metabolic profiles of bile acids in urine using a lipophilic anion exchanger and computerized gas-liquid chromatography-mass spectrometry. J Lipid Res 18 339-362... 

Total fatty acids were liberated by subjecting Salmonella minnesota Re lipopolysaccharide (or free lipid A) to acidic (4 N HC1, 5 h, 100°C) followed by alkaline (1 N NaOH, 1 h, 100°C) hydrolysis. After extraction (chloroform), the free fatty acids were converted into their methyl esters (diazomethane) and analysed by combined gas-liquid chromatography/mass spectrometry. Alternatively, the fatty acids of lipid A are transesterified by treatment of lipopolysaccharide with methanolic HC1 (2 N HC1 in water-free CHaOH, 18 h, 85°C). By these procedures the following fatty acids were identified (in approximate amounts relative to 2 moles glucosamine) dodecanoic (12 0, 1.1 mole), tetradecanoic (14 0, 0.8 mole), hexadecanoic (16 0, 0.9 mole), 2-hydroxytetradecanoic (2-OH-l4 0, 0.1 mole), and 3-hydroxytetradecanoic acid (3-OH-14 0, 4 moles). In total, therefore, approximately 7 moles of fatty acids are present per mole of lipid A backbone. The stereochemistry of the hydroxylated fatty acids was determined by gas-liquid chromatography of their diastereomeric methoxyacyl-L-phenylethylamide derivatives (24). It was found that 2-hydroxyte-tradecanoic acid possesses the-Ts), and the predominating 3-hydroxytetradecanoic acid the (R) configuration. 

Methomyl Chloroform Gas liquid chromatography-mass spectrometry. Limit of detection 1 ixg/kg [310]... 

Preliminary examinations of dextran structures were conducted by optical rotation, infrared spectroscopy and periodate-oxidation reactions. More detailed results can be achieved by methylation analysis [19]. The hydroxyl groups are methylated with methyl iodide after activation with sodium methylsulfinyl carbanion (Fig. 2). The methyl dextran is hydrolysed to the corresponding different methylated monosaccharides, which are furthermore reduced and peracetylated. The resulting alditol acetates of methylated sugars are separated by gas chromatography and identified by their retention times. In particular, a combined capillary gas-liquid chromatography/mass... 

Satouchi, K. and Saito, K. (1979) Use of f-butyldimethylchlorosilane/imidazole reagent for identification of molecular species of phospholipids by gas-liquid chromatography-mass spectrometry, Biomed. Mass Spectrom. 6, 396-402. 

Niemela K, Sjostrom E (1986) Simultaneous identification of aromatic and aliphatic low molecular weight compounds from alkali pulp liquor by capillary gas-liquid chromatography-mass spectrometry Holzforschung 40 361-368... 

R. Takano, K. Kamei-Hayashi, S. Hara, and S. Hirase, Assignment of the absolute configuration of partially methylated galactoses by combined gas-liquid chromatography—mass spectrometry, Biosci. Biotech. Biochem., 57 (1993) 1195—1197. 

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