title: On-line coupling of solid-phase extraction to liquid chromatography-tandem mass spectrometry for the determination of macrolide antibiotics in environmental water.
abstract: An automated on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) system was developed for the determination of macrolide antibiotics including erythromycin (ETM), roxithromycin (RTM), tylosin (TLS) and tilmicosin (TMC) in environmental water samples. A Capcell Pak MF Ph-1 column packed with restricted access material (RAM) was used as SPE column for the concentration of the analytes and clean-up of the sample. One milliliter water sample was injected into the conditioned SPE column and the matrix was washed out with 3 mL high purity water. By rotation of the switching valve, macrolides (MLs) were eluted in the back-flush mode and transferred to the analytical column by the chromatographic mobile phase. The matrix effect was evaluated by the directly injection LC-MS and on-line SPE-LC-MS methods. The limits of detection (LODs) and limits of quantification (LOQs) obtained are in the range of 2-6 and 7-20 ng L(-1), respectively, which means that the proposed method is suitable for trace analysis of MLs at low level concentration. The intra- and inter-day precisions are in the range of 2.9-7.2% and 3.3-8.9%, respectively. In the three fortified levels (20, 200 and 2000 ng L(-1)), recoveries of MLs ranging from 86.5% to 98.3% are obtained.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 202 Haihe Road, Harbin 150090, China. dingjie123@hit.edu.cn
authors.forename: Jie
authors.initials: J
authors.lastname: Ding
authors.forename: Nanqi
authors.initials: N
authors.lastname: Ren
authors.forename: Ligang
authors.initials: L
authors.lastname: Chen
authors.forename: Lan
authors.initials: L
authors.lastname: Ding
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis*; D002138:Calibration; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods; D018942:Macrolides / Q000032:analysis*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D014874:Water Pollutants, Chemical