Gas chromatography—mass spectrometry of aldoses as O-methoxime, O-2-methyl-2-propoxime and O-n-butoxime pèrtrifluoroacetyl derivatives on OV-225 with methylpropane as ionization agent

Abstract Pentoses have been identified by gas chromatography—mass spectrometry using chemical ionization by methylpropane of the O-methoxime, O-2-methyl-2-propoxime and O-n-butoxime pertrifluoroacetyl derivatives, separated on a glass capillary column wall coated with OV-225. Each pentose gave two peaks, the syn (Z) and the anti (E) alkoxime. The syn derivatives of O-2-methyl-2-propoximes give shorter retention times than the corresponding derivatives of O-methoximes. The fragmentation patterns are discussed. M + 1 gives the most intense peak.