Figure 4.59
Some examples of separations by HPCE. (a) CZE BSA peptide
map. Conditions: 20 mM phosphate, pH 7, V = 25 kV, i = 16 μA,
1 = 50 cm, L = 57 cm, id = 50 μm with 3X extended pathlength
detection cell, λ = 200 nm. (b) MECC separation of cold-relief
medicine constituents. Conditions: 20 mM phosphate-borate,
100 mM SDS, pH 9, V = 20 kV, L = 65 cm, i.d. = 50 μm, λ = 210 nm.
(c) CGE of 1 kbp ladder using minimally cross-linked
polyacrylamide. Conditions: Bis-cross-linked polyacrylamide
(3% T, 0.5% C), 100 mM Tris-borate, pH 8.3, E = 250 V/cm,
i = 12.5 μA, 1 = 30 cm, L = 40 cm, i.d. = 75 μm, λ = 260 nm,
polyacrylamide coated capillary. (d) CIEF of standard protein
mixture. Polyacrylamide coated capillary.Applications of Capillary Electrochromatography
As yet, the number of applications is limited but is likely to grow as instrumentation, mostly based on
existing CE systems, and columns are improved and the theory of CEC develops. Current examples
include mixtures of polyaromatic hydrocarbons, peptides, proteins, DNA fragments, pharmaceuticals
and dyes. Chiral separations are possible using chiral stationary phases or by the addition of
cyclodextrins to the buffer (p. 179). In theory, the very high efficiencies attainable in CEC mean high
peak capacities and therefore the possibility of separating complex mixtures of hundreds of