N. Chen et al., ELECTROPHORETIC SELECTIVITY AS A FUNCTION OF OPERATING PARAMETERS IN FREE SOLUTION CAPILLARY ELECTROPHORETIC SEPARATION OF DIPEPTIDES, Journal of liquid chromatography, 16(17), 1993, pp. 3609-3622
Free-solution capillary electrophoretic separation of some dipeptides
were carried out under acidic and alkaline conditions. The reproducibi
lity of two migration parameters (migration time and relative migratio
n time) for some dipeptides was examined under various operating condi
tions. ''The electrophoretic selectivity ''or relative migration time
which is defined as the ratio of the migration time of test component
to that of the reference standard shows better reproducibility than mi
gration time. In addition, better reproducibility in migration times w
as obtained -from the capillary previously stored in acidic conditions
for a certain period of time. Migration times of a neutral marker (t(
o)) and dipeptides (t(m)) and relative migration times were examined a
s functions of operating column temperature and applied current(I). A
quantitative linear correlation between logarithm of migration time (l
og t(o) or log t(m)) and the reciprocal of column temperature (1/T) un
der constant applied voltage has been derived . Plots of the reciproca
l of migration times (1/t(m)) for dipeptides versus the applied curren
t(I) yielded parallel lines. The parallel linear relationships between
log t(m) and 1/T, 1/t(m) and I implied that the electrophoretic selec
tivity was independent of column temperature and operating current.