title: Solid phase extraction using magnetic core mesoporous shell microspheres with C18-modified interior pore-walls for residue analysis of cephalosporins in milk by LC-MS/MS.
abstract: A fast and effective extraction method has been developed for measuring the residue of cephalosporins (cefalexin, cefazolin, cefoperazone) in milk by using magnetic core-mesoporous shell microspheres with C18-functionalized interior pore-walls (C18-Fe3O4@mSiO2) as adsorbent. With no need for any protein precipitation procedure, the cephalosporins were directly adsorbed onto the C18-Fe3O4@mSiO2 microspheres through hydrophobic interaction with C18-groups (Octadecyl functional groups) functionalized in the interior walls of mesopore channels while the abundant proteins in milk sample were excluded out of the channel due to the size exclusion effect. Thereafter, the cephalosporins-absorbed C18-Fe3O4@mSiO2 microspheres were rapidly isolated by placing a magnet, and followed by liquid chromatography-tandem mass spectrometry analysis after eluted by methanol. Various parameters which could affect the extraction performance were optimised. The newly developed extraction method was successfully applied in determination of cephalosporin residues in milk samples, offering a valuable alternative to simplify and speed up the sample preparation step.
authors.affiliation: Department of Pharmaceutical Analysis, School of Pharmacy, Fudan University, No. 826 Zhangheng Road, Shanghai 201203, PR China.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Pharmaceutical Analysis, School of Pharmacy, Fudan University, No. 826 Zhangheng Road, Shanghai 201203, PR China.
authors.forename: Yingjia
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Pharmaceutical Analysis, School of Pharmacy, Fudan University, No. 826 Zhangheng Road, Shanghai 201203, PR China.
authors.forename: Meiyan
authors.initials: M
authors.lastname: Zhao
authors.affiliation: Department of Biology, Dezhou University, Shangdong 253023, PR China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Pharmaceutical Analysis, School of Pharmacy, Fudan University, No. 826 Zhangheng Road, Shanghai 201203, PR China. Electronic address: yanli@fudan.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Pharmaceutical Analysis, School of Pharmacy, Fudan University, No. 826 Zhangheng Road, Shanghai 201203, PR China.
authors.forename: Gengli
authors.initials: G
authors.lastname: Duan
mesh_terms: D000327:Adsorption; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification*; D002511:Cephalosporins / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005506:Food Contamination / Q000032:analysis; D059346:Magnets / Q000737:chemistry; D008863:Microspheres; D008892:Milk / Q000737:chemistry*; D010573:Pesticide Residues / Q000737:chemistry / Q000302:isolation & purification*; D016062:Porosity; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D010573:Pesticide Residues
keywords: C18-modified interior pore-walls; Cephalosporins; Extraction; LC–MS/MS; Magnetic mesoporous microspheres; Milk samples