title: Multiresidue analysis of beta2-agonist in human and calf urine using multimodal solid-phase extraction and high-performance liquid chromatography with electrochemical detection.
abstract: Various beta2-agonists are used as illegal growth promoters in man and in animals. We developed a multiresidue procedure for the analysis of four beta-agonists in human and calf urine. The sample was pre-extracted with an Extrelut column at alkaline pH. The beta-agonists were eluted with a mixture of tert.-butylmethyl ether and hexane. Then the extract was further cleaned with a mixed mode SPE column, or with a combination of immunoaffinity chromatography (IAC) and the mixed mode SPE column. The IAC column contained antibodies against salbutamol, which were suitable for multiresidue extractions. The extract was then brought onto a mixed mode SPE column at an acidic pH. The column was washed with 70% methanol in water. Thereafter, the beta-agonists were eluted with ammoniated ethanol-hexane. The extract was analysed with an HPLC method with electrochemical detection. The beta-agonists were separated on a reversed-phase column using a mobile phase buffered at pH 5.5 and containing an ion-pair reagent. Recoveries were higher when the IAC procedure was not performed (90-105% vs. 65-75%), but the extracts were cleaner when the latter step was included. Detection limits in human and calf urine were in the low ng/ml range. The study indicated that beta2-agonists can be analysed in human and calf urine without the selectivity of a mass spectrometer, but that comprehensive clean-up is required to avoid the interference of urine matrix components.
authors.affiliation: University Centre for Pharmacy, Department of Analytical Chemistry and Toxicology, Groningen, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Koole
authors.forename: J
authors.initials: J
authors.lastname: Bosman
authors.forename: J P
authors.initials: JP
authors.lastname: Franke
authors.forename: R A
authors.initials: RA
authors.lastname: de Zeeuw
mesh_terms: D058666:Adrenergic beta-2 Receptor Agonists; D000318:Adrenergic beta-Agonists / Q000652:urine*; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004350:Drug Residues / Q000032:analysis; D004563:Electrochemistry; D006801:Humans; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D000318:Adrenergic beta-Agonists