title: Per-O-methylation of neutral carbohydrates directly from aqueous samples for gas chromatography and mass spectrometry analysis.
abstract: Per-O-methylation of neutral carbohydrates in one step by adding dimethyl sulfoxide, powdered sodium hydroxide, and methyl iodide directly to aqueous sample is described. The influence of the water on the methylation reaction is investigated. Solid powdered sodium hydroxide is very hygroscopic and can scavenge the water from sample if an additional excess of sodium hydroxide is added. The degree of per-O-methylation of carbohydrates is checked by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Gas chromatography-mass spectrometry analysis of mono- and disaccharides from grape juice is presented.
authors: Department of Chemistry, West University of Timisoara, Strada Pestalozzi 16, RO-300115 Timisoara, Romania. iciucanu@cbg.uvt.ro <iciucanu@cbg.uvt.ro>
authors: Ionel
authors: I
authors: Ciucanu
authors: Rodica
authors: R
authors: Caprita
mesh_terms: D001628:Beverages; D002241:Carbohydrates / Q000737:chemistry*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D005632:Fructose / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D005947:Glucose / Q000032:analysis; D006847:Hydrocarbons, Iodinated / Q000737:chemistry; D007477:Ions; D013058:Mass Spectrometry / Q000379:methods; D008745:Methylation; D012972:Sodium Hydroxide / Q000737:chemistry; D013395:Sucrose / Q000032:analysis; D027843:Vitis; D014867:Water / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D006847:Hydrocarbons, Iodinated; D007477:Ions; D014867:Water; D005632:Fructose; D012972:Sodium Hydroxide; D013395:Sucrose; C014055:methyl iodide; D005947:Glucose; D004121:Dimethyl Sulfoxide