T. Nakagama et al., Photo-responsive retention behavior of azobenzene-modified cyclodextrin stationary phase in micro-HPLC, ANAL SCI, 17(1), 2001, pp. 119-124
An azobenzene-modified gamma -cyclodextrin stationary phase (Az gamma -CDSP
) was prepared and its photo- and temperature responses for the retention o
f perylene and pentacene were investigated using a mixture of methanol and
water as the mobile phase in micro-HPLC. The retention of perylene slightly
increased, whereas that of pentacene significantly decreased by UV light i
rradiation to Az gamma -CDSP. These retentions recovered upon irradiation w
ith visible light. Both retentions decreased upon an increase in the column
temperature. It was presumed that the trans-azobenzene moiety acts as a pr
eventive cap for perylene and a spacing for pentacene in filling the CD cav
ity. An azobenzene-modified stationary phase changed its retention behavior
with the column temperature and the light irradiation. An improvement in t
he micro-HPLC system acid the optimization of the molecular structure of th
e photo-responsive stationary phase would provide selective retention contr
ol by the irradiation of light in micro-separation systems.