Stacking enhanced determination of steroids by CE.
This study outlines a simple method for pH-mediated stacking of natural and synthetic steroids facilitated with carboxymethyl-beta-CD. Sample stacking (10 kV, 60 s) is accomplished with 23 mM carboxymethyl-beta-CD in 50 mM 3-[cyclohexylamino]-1-propanesulfonic acid buffered at pH 10. Following stacking, steroidal compounds are separated in less than 5 min with a running buffer of 13 mM hydroxypropyl-beta-CD, 30 mM SDS in 200 mM phosphate buffered at pH 2.5. Using a 60 s electrokinetic injection, the limits of detection of estradiol, ethynyl estradiol, estrone, hydroxyprogesterone, progesterone, and 11-ketotestosterone range from 2 to 14 nM. For all steroids, the within-day and day-to-day reproducibility in migration time is < or =1 and < or =2% RSD, respectively. The within-day and day-to-day reproducibility in peak area is < or =9 and < or =22% RSD, respectively. The method is applied to fish plasma and holds potential to profile multiple steroids in a single biological sample.
C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV 26506, USA.
Liliya
L
Bykova
Lisa A
LA
Holland
D000818:Animals; D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods; D005399:Fishes; D015203:Reproducibility of Results; D013256:Steroids / Q000032:analysis* / Q000097:blood; D047392:beta-Cyclodextrins / Q000737:chemistry
D013256:Steroids; D047392:beta-Cyclodextrins; C441457:carboxymethyl-beta-cyclodextrin