The solvents for the gradient elution were acetonitrile
and 1 M-ammonium acetate buffer, pH 5.16.
The pH was adjusted with 1 M-acetic acid. A 15-min
linear gradient from 13% (v/v) acetonitrile to 30%
acetonitrile in the ammonium acetate buffer, followed
by an isocratic elution at 30% acetonitrile for
a further 15 min was used for separations performed
on the 25 cm x 5 mm column. For separations
carried out on the 10cm x 5mm column a 15-min
Column, ODS-Hypersil (25 cm x 5 mm); mobile
phase, 1 5-min gradient elution from 13% acetonitrile
(in 1 M-ammonium acetate, pH 5.16) to 30%
acetonitrile, then isocratic elution at 30% acetonitrile
for 15 min; flow rate, 1 ml/min; detection, u.v.
404 nm.