[Study of large-volume electrokinetic injection of capillary zone electrophoresis by using transient isotachophoresis].
A sample pre-concentration method that combined field-amplified sample injection (FASI) induced by acetonitrile with transient isotachophoresis was applied to achieve effective concentration and the separation of cations in high-salt samples. Several important factors are discussed, such as buffer systems, terminating ions, column effective length and injection time of sample and terminating solution. A capillary column of 50 microm i. d. x 65 cm (effective length of 50 cm) was employed. Solutions of 400 mmol/L LiAc-HAc (pH 4.5) and 400 mmol/L beta-alanine-HAc (pH 4.5) were used as buffer solution and terminating electrolyte, respectively. The injection times of sample solution and terminating electrolyte were 270 and 90 s, respectively. Compared with conventional electrokinetic injection, the sensitivity of the proposed method was improved about 280-fold. The detection limits of propranolol and metoprolol achieved 2 x 10(-3) and 8 x 10(-3) mg/L, respectively.
Li
Yun
Y
Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
He
Youzhao
Y
D000097:Acetonitriles / Q000737:chemistry; D000959:Antihypertensive Agents / Q000032:analysis*; D002021:Buffers; D002412:Cations / Q000737:chemistry; D004586:Electrophoresis / Q000379:methods; D019075:Electrophoresis, Capillary / Q000379:methods*; D017022:Flow Injection Analysis / Q000379:methods; D006863:Hydrogen-Ion Concentration; D008790:Metoprolol / Q000032:analysis*; D011433:Propranolol / Q000032:analysis*; D012965:Sodium Chloride / Q000737:chemistry; D013696:Temperature; D013997:Time Factors
D000097:Acetonitriles; D000959:Antihypertensive Agents; D002021:Buffers; D002412:Cations; D012965:Sodium Chloride; D011433:Propranolol; D008790:Metoprolol; C032159:acetonitrile