Method to calculate micellar phase residence time [t(mic) = t(mc) k''', tim
e spent by the analyte in the micellar phase] and aqueous phase residence t
ime [t(aq) = t(0) (1 - k"'), time spent by the analyte in the aqueous phase
] was developed, where t(m), t(o) and t(mc) are the migration time of the a
nalyte, the flow marker and the micelles, respectively. It was proved that
migration time of the analyte is the sum of the phase residence times [t(m)
= t(mic) + t(aq) = t(0) (1 - k"') + k"' t(mc)]. Two physico-chemical param
eters characterizing hydrophobicity of the analyte, namely the ratio of the
moles of the analyte in the micellar (n(mc)) and aqueous (n(aq)) phase (n(
mc)/n(aq) = t(mi)c/t(aq)) as well as distribution coefficient (K) have also
been determined from the phase residence times. Good correlation was found
between the micellar phase residence times and computer calculated hydroph
obicity values (S) in the case of hydroxy- and aldehyde benzene derivatives
, benzene- and alkyl phenone homolog series and in the case of seven hydrop
hobic protected peptides. Comparison of hydrophobicity values and phase res
idence times showed that the higher the hydrophobicity of the analyte the l
onger the time spent in the micellar (hydrophobic) phase. The micellar phas
e residence time determinable experimentally in MEKC reflects the hydrophob
icity of the molecule investigated.