Chiral recognition and the determination of optical purity of a-phenylethylamine using monosaccharide as a chiral selector under liquid secondary ion mass spectral conditions

Abstract

Naturally available monosaccharides, D-mannose, D-galactose and D-glucose, have been used for the first time as chiral co-matrices for chiral recognition of α-phenylethylamine. The liquid secondary ion (LSI) mass spectra of a mixture of D-mannose and (R)- or (S)-α-phenylethylamine in the presence of benzylamine as reference compound and glycerol as matrix showed [(mannose + (R)- / (S)-α-phenylethylamine + H)–H2O]⁺ (a) and [(mannose + benzylamine + H)–H2O]⁺ (b) ions. The significant difference was observed in the relative peak intensity (RPI) values calculated from the ion abundances of ion a and b. The RPI values for (R)- and (S)-α-phenylethylamine are RPI_R = 0.79 and RPI_S = 1.34, respectively. The efficiency of the chiral recognition property of D-mannose is demonstrated in estimating the enantiomeric excess of α-phenylethylamine.