title: Sensitive enantioanalysis of β-blockers via field-amplified sample injection combined with water removal in microemulsion electrokinetic chromatography.
abstract: In this study, an on-line sample preconcentration technique, field-amplified sample injection combined with water removal by electroosmotic flow (EOF) pump, was applied to realize a highly sensitive chiral analysis of β-blocker enantiomers by MEEKC. The introduction of a water plug in capillary before the electrokinetic injection provided the effective preconcentration of chiral compounds. And then the water was moving out of the column from the injection end under the effect of the EOF, which avoided dilution of the stacked β-blocker enantiomers concentration suffering from the presence of water in separation buffer. Moreover, the addition of H3 PO4 and methanol in the sample solution greatly improved the enhancement efficiency further. Under optimized conditions, more than 2700-fold enhancement in sensitivity was obtained for each enantiomer of bupranolol (BU), alprenolol (AL), and propranolol (PRO) via electrokinetic injection. LODs were 0.10, 0.10, 0.12, 0.11, 0.02, and 0.02 ng/mL for S-BU, R-BU, S-AL, R-AL, S-PRO, and R-PRO, respectively. Eventually, the proposed method was successfully applied to the determination of BU, AL, and PRO in serum samples with good recoveries ranging from 93.4 to 98.2%.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, P. R. China; Department of Chemistry, Lanzhou University, Lanzhou, P. R. China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Ma
authors.forename: Huige
authors.initials: H
authors.lastname: Zhang
authors.forename: Zia Ur
authors.initials: ZU
authors.lastname: Rahman
authors.forename: Weifeng
authors.initials: W
authors.lastname: Wang
authors.forename: Xi
authors.initials: X
authors.lastname: Li
authors.forename: Hongli
authors.initials: H
authors.lastname: Chen
authors.forename: Xingguo
authors.initials: X
authors.lastname: Chen
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification*; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D057230:Limit of Detection; D016014:Linear Models; D015203:Reproducibility of Results; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry
chemical_list: D000319:Adrenergic beta-Antagonists; D014867:Water
keywords: Enantioseparation; Field-amplified sample injection; Microemulsion electrokinetic chromatography; β-Blockers