Photo-response assisted enantiomer separations on an azobenzene-modified gamma-cyclodextrin stationary phase in micro-HPLC.
The photo-responses of the retention and enantioseparation of several optical isomers were evaluated using an azobenzene-modified gamma-cyclodextrin stationary phase (Az gamma-CDSP) in micro-HPLC. UV light irradiation induced a decrease in the retention and the chiral selectivity for N-(3,5-dinitrobenzoyl)-1-phenylethylamine (DNBPEA) and N-(3,5-dinitrobenzoyl)-1-(1-naphtylethyl)amine (DNBNEA), while an increase was induced for dansylphenylalanine (DnsPhe) using a mixture of methanol and aqueous phosphate buffer as the mobile phase. No changes in the retention and the enantiomer separation of benzoin were observed with UV light irradiation. The retention behaviors were recovered by visible-light irradiation. It was speculated that the main factor of the change in the retention behavior was a change in the pi-pi interaction due to the azobenzene moiety of the stationary phase with photo-irradiation. Comparing the retention behavior before and after UV light irradiation, a suitable condition for obtaining a better resolution and enantiomer separation would be chosen using Az gamma-CDSP.
Nakagama
Tatsuro
T
Division of Applied Chemistry, Graduate School of Engineering, Tokyo Metropolitan University, Hachioji, Japan. nakagama-tatsuro@c.metro-u.ac.jp
Yamaguchi
Atsutoshi
A
Hirasawa
Kazuya
K
Yoshida
Koji
K
Uchiyama
Katsumi
K
Hobo
Toshiyuki
T
D001391:Azo Compounds; D001555:Benzene Derivatives; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003505:Cyclodextrins / Q000737:chemistry* / Q000302:isolation & purification; D007202:Indicators and Reagents; D008832:Microchemistry / Q000379:methods; D013237:Stereoisomerism
D001391:Azo Compounds; D001555:Benzene Derivatives; D003505:Cyclodextrins; D007202:Indicators and Reagents