Per-O-methylation of neutral carbohydrates directly from aqueous samples for gas chromatography and mass spectrometry analysis

Anal Chim Acta. 2007 Feb 28;585(1):81-5. doi: 10.1016/j.aca.2006.12.015. Epub 2006 Dec 19.


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.

MeSH terms

  • Beverages
  • Carbohydrates / chemistry*
  • Chemistry Techniques, Analytical / methods*
  • Dimethyl Sulfoxide / chemistry
  • Fructose / analysis
  • Gas Chromatography-Mass Spectrometry / methods*
  • Glucose / analysis
  • Hydrocarbons, Iodinated / chemistry
  • Ions
  • Mass Spectrometry / methods
  • Methylation*
  • Sodium Hydroxide / chemistry
  • Sucrose / analysis
  • Vitis
  • Water / chemistry*


  • Carbohydrates
  • Hydrocarbons, Iodinated
  • Ions
  • Water
  • Fructose
  • Sodium Hydroxide
  • Sucrose
  • methyl iodide
  • Glucose
  • Dimethyl Sulfoxide