title: Determination of beta-lactam antibiotics in milk using micro-flow chemiluminescence system with on-line solid phase extraction.
abstract: In this paper, a chemiluminescence (CL) micro-flow system combined with on-line solid phase extraction (SPE) is presented for determination of beta-lactam antibiotics (penicillin, cefradine, cefadroxil, cefalexin) in milk. It is based on the enhancement effect of beta-lactam antibiotics on the luminol-K3Fe(CN)6 CL system. The micro-flow system was fabricated from two polymethyl methacrylate (PMMA) plates (50 mm x 40 mm x 5 mm) with the microchannels of 200 microm wide and 150 microm deep. C18-modified silica gel was packed into the microchannel (length: 10 mm; width: 1 mm; depth: 500 microm) to serve as SPE device. Extraction and preconcentration of the analytes were carried out using on-line SPE micro-flow system and the selectivity of CL detection was improved. The detection limits were 0.5 microg mL(-1) of penicillin, 0.04 microg mL(-1) of cefradine, 0.08 microg mL(-1) of cefadroxil and 0.1 microg mL(-1) of cefalexin. The proposed method was also applied to analyze the beta-lactam antibiotics in milk. Experimental results were in good agreement with those obtained by high performance liquid chromatography (HPLC) method with UV detection.
authors.affiliation: Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Zhujun
authors.initials: Z
authors.lastname: Zhang
authors.forename: Zuoqin
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000302:isolation & purification; D017022:Flow Injection Analysis; D020407:Internet; D008163:Luminescent Measurements / Q000295:instrumentation* / Q000379:methods*; D008892:Milk / Q000737:chemistry*; D052616:Solid Phase Extraction / Q000295:instrumentation* / Q000379:methods*; D047090:beta-Lactams / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams