title: Automated liquid chromatographic determination of atenolol in plasma using dialysis and trace enrichment on a cation-exchange precolumn for sample handling.
abstract: A fully automated method involving dialysis combined with trace enrichment was developed for the liquid chromatographic (LC) determination of atenolol, a hydrophilic beta-blocking agent, in human plasma. The plasma samples were dialysed on a cellulose acetate membrane and the dialysate was reconcentrated on a short trace enrichment column (TEC) packed with a strong cation-exchange material. All sample handling operations can be executed automatically by a sample processor (ASTED system). After TEC conditioning, the plasma sample, to which the internal standard (sotalol, another hydrophilic beta-blocker) was automatically added, was introduced in the donor channel and dialysed in the static/pulsed mode. The dialysis liquid consisted of 4.3 mM phosphoric acid. When the dialysis process was discontinued, the analytes were eluted from the TEC in the back-flush mode by the LC mobile phase and transferred to the analytical column, packed with octyl silica. The LC mobile phase consisted of phosphate buffer, pH 7.0-methanol (81:19; v/v) with 1-octanesulfonate. Atenolol and the internal standard were monitored photometrically at 225 nm. The different parameters influencing the dialysis and trace enrichment processes were optimised with respect to analyte recovery. The influence of two different kinds of cation-exchange material on analyte recovery and peak efficiency was also studied. The method was then validated in the concentration range 25-1000 ng/ml. The mean recovery for atenolol was 65% and the limit of quantitation was 25 ng/ml.
authors.affiliation: Department of Analytical and Pharmaceutical Chemistry, Institute of Pharmacy, University of Liège, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Chiap
authors.forename: B M
authors.initials: BM
authors.lastname: Buraglia
authors.forename: A
authors.initials: A
authors.lastname: Ceccato
authors.forename: P
authors.initials: P
authors.lastname: Hubert
authors.forename: J
authors.initials: J
authors.lastname: Crommen
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000032:analysis; D001262:Atenolol / Q000097:blood*; D001331:Automation; D002852:Chromatography, Ion Exchange / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D003956:Dialysis / Q000379:methods; D015314:Dialysis Solutions / Q000737:chemistry; D006801:Humans; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D013048:Specimen Handling; D013997:Time Factors
chemical_list: D000319:Adrenergic beta-Antagonists; D015314:Dialysis Solutions; D001262:Atenolol