title: Determination of clenbuterol in bovine liver by combining matrix solid-phase dispersion and molecular imprinted solid-phase extraction followed by liquid chromatography/electrospray ion trap multiple-stage mass spectrometry.
abstract: Matrix solid-phase dispersion (MSPD) is a new sample pretreatment for solid samples. This technique greatly simplifies sample pretreatment but, nonetheless, the extracts often still require an extra cleanup step that is both laborious and time-consuming. The potential of combining MSPD with molecularly imprinted solid-phase extraction (MISPE) was investigated in this study. Liver samples were ground in a mortar with C18 sorbent and the homogenized mixture packed into an SPE cartridge and placed on top of a MISPE cartridge. Subsequently, clenbuterol was eluted from the MSPD cartridge onto the MISPE cartridge using acetonitrile containing 1% acetic acid. The ability of the molecularly imprinted polymer to selectively adsorb analyte in acetonitrile was exploited for re-extracting clenbuterol directly from this acetonitrile extract via the double cartridge tandem system. The analyte was eluted from the MISPE cartridge using acidified methanol. A clear eluate was obtained, which was subsequently evaporated, redissolved, and analyzed by HPLC electrochemical detection (ECD) or ion trap mass spectrometry (LC/IT-MS). The MISPE cartridge used in this study was imprinted using bromoclenbuterol, a structural analogue of clenbuterol, as the template. These MISPE cartridges showed excellent stability. The complete extraction procedure was rapid, and recoveries exceeded 90% for the target analyte. The method detection limit for the LC/IT-MS procedure was < 0.1 microg/kg. This method, therefore, satisfies the stringent requirements of European Union regulation EEC 2377/90.
authors.affiliation: Department of Analytical Chemistry and Toxicology, University Center for Pharmacy, Groningen, The Netherlands. carlo.crescenzi@anchem.su.se
authors.forename: C
authors.initials: C
authors.lastname: Crescenzi
authors.forename: S
authors.initials: S
authors.lastname: Bayoudh
authors.forename: P A
authors.initials: PA
authors.lastname: Cormack
authors.forename: T
authors.initials: T
authors.lastname: Klein
authors.forename: K
authors.initials: K
authors.lastname: Ensing
mesh_terms: D000318:Adrenergic beta-Agonists / Q000032:analysis*; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002976:Clenbuterol / Q000032:analysis*; D004563:Electrochemistry; D008099:Liver / Q000737:chemistry*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D000318:Adrenergic beta-Agonists; D002976:Clenbuterol