title: Molecularly imprinted solid-phase extraction of cephalexin from water-based matrices.
abstract: In the present paper, we describe the synthesis of a cephalexin (CFX) molecularly imprinted polymer (MIP), the direct application of the MIP to SPE for the determination of CFX (which is a beta-lactam antibiotic) in human urine and the use of the MIP in a tandem SPE system to determine CFX in river water. The molecularly imprinted polymers (MIP) showed cross-selectivity for amoxicillin (AMX; also a beta-lactam antibiotic). This allowed both CFX and AMX to be quantified in acidified human urine, with recoveries of 78 and 60% for CFX and AMX, respectively, when the urine samples were spiked with CFX and AMX at 4 mg/L. These analyses were facile because the molecularly imprinted solid-phase extraction (MISPE) extracts were clear compared to the nonpurified samples. In order to increase the sample volume for river water analyses, a tandem SPE system incorporating a commercially available sorbent was implemented. With this set-up, CFX was determined with recoveries in excess of 50% when 200 mL of acidified river water samples spiked at 10 microg/L with CFX were percolated through the tandem system.
authors.affiliation: Departament de Química Analítica i Química Orgànica, Universitat Rovira i Virgili, Tarragona, Spain.
authors.forename: Antoni
authors.initials: A
authors.lastname: Beltran
authors.forename: Núria
authors.initials: N
authors.lastname: Fontanals
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Marcé
authors.forename: Peter A G
authors.initials: PA
authors.lastname: Cormack
authors.forename: Francesc
authors.initials: F
authors.lastname: Borrull
mesh_terms: D000658:Amoxicillin / Q000032:analysis; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002506:Cephalexin / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D054802:Molecular Imprinting; D015394:Molecular Structure; D010404:Penicillin V / Q000032:analysis; D011108:Polymers / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods*; D014556:Urine / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D000900:Anti-Bacterial Agents; D011108:Polymers; D014874:Water Pollutants, Chemical; D014867:Water; D000658:Amoxicillin; D002506:Cephalexin; D010404:Penicillin V