Me. Roche et al., ENHANCED THROUGHPUT WITH CAPILLARY ELECTROPHORESIS VIA CONTINUOUS-SEQUENTIAL SAMPLE INJECTION, Analytical chemistry, 69(1), 1997, pp. 99-104
A significant fraction of the total analysis time (injection-to-inject
ion) in capillary electrophoresis is dedicated to a rigorous between-r
un capillary rinsing/regeneration procedure, This is of particular imp
ortance with CE-based assays developed for high-throughput analysis of
clinical samples. In this study, we examine the necessity of a betwee
n-run rinsing step when detergent is present in the separation buffer,
Using three model analyte systems (hypoglycemic drug standards, urina
ry estrogen standards, fasted normal human urine), the reproducibility
for migration time (MT), peak area (PA), and peak height (PH) with se
paration in a borate/phosphate buffer containing 75 mM sodium cholate
was found to be acceptable in the absence of between-ran capillary cle
ansing, Continuous-sequential injection of hypoglycemic drug standards
over the course of 39 consecutive runs without between-run capillary
regeneration showed acceptable reproducibility. The average percent co
efficient of variance values associated with MT(rel(MeOH)), PA, and PH
over 39 consecutive runs were 2.22, 3.27, and 3.51%, respectively, In
excess of 100 continuous-sequential injections could be performed in
this manner without any significant effects on electroosmotic flow or
reproducibility. Exclusivity of these results was ruled out with the c
ontinuous-sequential injection of the urinary estrogen and the human u
rine analyte systems under the same conditions, both of which yielded
comparable results, The ability to circumvent or eliminate capillary r
insing procedures when detergent is a component of the separation buff
er presents the possibility of decreasing the total analysis time (inj
ection-to-injection) with certain analyte systems, the result of which
will be to enhance sample throughput by 2-3-fold on single-capillary
instrumentation.