title: Zeolite imidazolate framework-8 as sorbent for on-line solid-phase extraction coupled with high-performance liquid chromatography for the determination of tetracyclines in water and milk samples.
abstract: Zeolite imidazolate framework-8 (ZIF-8) was used as the novel sorbent for on-line solid-phase extraction coupled with high-performance liquid chromatography (HPLC) for the determination of oxytetracycline (OTC), tetracycline (TC) and chlorotetracycline (CTC) in water and milk samples. 390mg of ZIF-8 was packed into a stainless steel column (3cm long×4.6mm i.d.) which was mounted on the HPLC injector valve to replace the sample loop. On-line solid-phase extraction of OTC, TC and CTC was achieved by loading sample solution at a flow rate of 3.0mLmin(-1) for 10min with the aid of a flow-injection system. The extracted analytes were subsequently eluted into a C18 analytical column (25cm long×4.6mm i.d.) for HPLC separation under isocratic condition with a mobile phase (10% MeOH-20% ACN-70% 0.02molL(-1) oxalic acid solution) at a flow rate of 1.0mLmin(-1). Under optimized conditions, the developed method gave the enhancement factors of 35-61, the linearity range of 5-1000μgL(-1), the detection limits of 1.5-8.0μgL(-1), quantification limits of 5.0-26.7μgL(-1), uncertainties of 0.9-1.1μgL(-1), and the sample throughput of 4 samples h(-1). The recoveries of OTC, TC and CTC at 50μgL(-1) in water and milk samples ranged from 70.3% to 107.4%.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Synergetic Innovation Center of Chemical Science and Engineering (Tianjin), and Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin 300071, China.
authors.forename: Xue-Qing
authors.initials: XQ
authors.lastname: Yang
authors.forename: Cheng-Xiong
authors.initials: CX
authors.lastname: Yang
authors.forename: Xiu-Ping
authors.initials: XP
authors.lastname: Yan
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification*; D002751:Chlortetracycline / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D057230:Limit of Detection; D008892:Milk / Q000737:chemistry*; D010118:Oxytetracycline / Q000302:isolation & purification*; D052616:Solid Phase Extraction / Q000379:methods*; D013752:Tetracycline / Q000302:isolation & purification*; D014867:Water / Q000032:analysis*; D017641:Zeolites / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D014867:Water; D017641:Zeolites; D013752:Tetracycline; D002751:Chlortetracycline; D010118:Oxytetracycline
keywords: High-performance liquid chromatography; Solid phase extraction; Tetracyclines; Water and milk samples; Zeolite imidazolate framework-8