title: On-line preconcentration and enantioseparation of thalidomide racemates by CEC with the hyphenation of octyl and norvancomycin monoliths.
abstract: A method was developed for simultaneous preconcentration and chiral separation of thalidomide enantiomers in human urine by CEC in combination with self-concentration and solvent gradient effects. A 4 cm long octyl (C8) monolithic column was hyphenated with a 15 cm long norvancomycin (NVC)-bonded monolithic column via a fluorinated ethylene-propylene interface. Sample solution was injected into the C8 monolithic column, the two thalidomide enantiomers were first preconcentrated on the C8 monolithic column, and then separated with a further concentration on the NVC-bonded monolithic column by CEC. Injection of 34.8 mm plug of sample solution gave 278- and 298-fold enhancement in sensitivity, and detection limits of 90 and 94 microg/L for the two thalidomide enantiomers. Peak areas of the two isomers were linear in a range of 0.5-50 mg/L. The precision for five replicate injections of 10 mg/L were 0.8-0.9 and 1.1-2.3% for the migration time and peak height, respectively. The developed method was applied to the determination of racemic thalidomide in spiked human urine samples.
authors.affiliation: Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin, P. R. China.
authors.forename: An-Na
authors.initials: AN
authors.lastname: Tang
authors.forename: Xiao-Nan
authors.initials: XN
authors.lastname: Wang
authors.forename: Guo-Sheng
authors.initials: GS
authors.lastname: Ding
authors.forename: Xiu-Ping
authors.initials: XP
authors.lastname: Yan
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D053801:Capillary Electrochromatography / Q000379:methods*; D006801:Humans; D011138:Polytetrafluoroethylene / Q000031:analogs & derivatives / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013237:Stereoisomerism; D013792:Thalidomide / Q000737:chemistry* / Q000652:urine*; D014640:Vancomycin / Q000031:analogs & derivatives / Q000737:chemistry; D005465:Fluorocarbon Polymers
chemical_list: D000097:Acetonitriles; D011138:Polytetrafluoroethylene; D013792:Thalidomide; D014640:Vancomycin; C096305:fluorinated ethylene propylene; D005465:Fluorocarbon Polymers; C511195:norvancomycin