Quantification of hydroxy groups in carbohydrates using gas-phase N2 adsorption

Gas-phase N-2 adsorption of mass-selected ions of carbohydrates containing 2-5 hydroxy groups was investigated using a tandem mass spectrometer equipped with an electrospray ionization source and cold ion trap. The maximum quantities of adsorbed N-2 molecules observed in the mass spectra were consistent with the quantities of hydroxy groups in the carbohydrates. The N-2 molecules were adsorbed on the hydrogen atoms of the hydroxy groups of the carbohydrates. The hydroxy groups of the carbohydrates were quantified using gas-phase N-2 adsorption. Gas-phase N-2-adsorption mass spectrometry detects free hydroxy groups on the surface of gas-phase ions.