Rodríguez-Díaz Rafael Carlos, Fernandez-Romero Juan Manuel, Aguilar-Caballos María Paz, Gómez-Hens Agustina
Department of Analytical Chemistry, "Marie Curie Annex" Building, Campus of Rabanales, University of Córdoba, E-14071 Córdoba, Spain.
J Agric Food Chem. 2006 Dec 27;54(26):9670-6. doi: 10.1021/jf0621368.
A liquid chromatography (LC) method with luminescence detection for the determination of eight quinolone antibiotics is reported. The system encompasses three consecutive steps: (a) chromatographic separation using reverse-phase mode (RP-LC), (b) postcolumn derivatization reaction, and (c) luminescence detection by monitoring fluorescence (FL) and time-resolved (TR) signals. The derivatization step is based on the reaction between quinolones and terbium(III) to form luminescent chelates, which were determined at lambda(ex) 340 and lambda(em) 545 nm (FL mode) or at lambda(ex) 281 and lambda(em) 545 nm (TR mode). Dynamic ranges of the calibration graphs, obtained with standard solutions of analytes and FL and TR modes, respectively, were 190-3500 and 316-2000 ng mL-1 for marbofloxacin, 8-3500 and 8.1-1500 ng mL-1 for ciprofloxacin, 6.2-3500 and 13-1500 ng mL-1 for danofloxacin, 7.4-3500 and 8.4-1500 ng mL-1 for enrofloxacin, 14-3500 and 20-2000 ng mL-1 for sarafloxacin, 12.5-3500 and 13.9-1200 ng mL-1 for difloxacin, 7.6-3500 and 13-3000 ng mL-1 for oxolinic acid, and 9-2000 and 130-3000 ng mL-1 for flumequine. Limit of detection values obtained using FL and TR modes, respectively, were 60 and 95 ng mL-1 for marbofloxacin, 2 and 2.4 ng mL-1 for ciprofloxacin, 1.9 and 3.9 ng mL-1 for danofloxacin, 2.2 and 2.5 ng mL-1 for enrofloxacin, 3.8 and 7 ng mL-1 for sarafloxacin, 4 and 4.2 ng mL-1 for difloxacin, 2.3 and 4 ng mL-1 for oxolinic acid, and 2.7 and 40 ng mL-1 for flumequine. The precision was established at two concentration levels of each analyte and expressed as the percentage of relative standard deviation with values ranging between 1.9 and 7.8%. The validation procedure for the analysis of samples was carried out using European Community recommendations, and the decision limit and detection capability were calculated for bovine whole milk. The method was applied to whole, semiskimmed, and skimmed milk samples spiked with the target analytes, and the recoveries ranged between 93.3 and 106.0%.
报道了一种采用发光检测的液相色谱（LC）方法用于测定8种喹诺酮类抗生素。该系统包括三个连续步骤：（a）使用反相模式（RP-LC）进行色谱分离，（b）柱后衍生化反应，以及（c）通过监测荧光（FL）和时间分辨（TR）信号进行发光检测。衍生化步骤基于喹诺酮类与铽（III）之间的反应形成发光螯合物，这些螯合物在λ（ex）340和λ（em）545 nm（FL模式）或λ（ex）281和λ（em）545 nm（TR模式）下进行测定。分别用分析物标准溶液以及FL和TR模式获得的校准曲线的动态范围，对于马波沙星为190 - 3500和316 - 2000 ng mL-1，对于环丙沙星为8 - 3500和8.1 - 1500 ng mL-1，对于达氟沙星为6.2 - 3500和13 - 1500 ng mL-1，对于恩诺沙星为7.4 - 3500和8.4 - 1500 ng mL-1，对于沙拉沙星为14 - 3500和20 - 2000 ng mL-1，对于二氟沙星为12.5 - 3500和13.9 - 1200 ng mL-1，对于恶喹酸为7.6 - 3500和13 - 3000 ng mL-1，对于氟甲喹为9 - 2000和130 - 3000 ng mL-1。分别使用FL和TR模式获得的检测限数值，对于马波沙星为60和95 ng mL-1，对于环丙沙星为2和2.4 ng mL-1，对于达氟沙星为1.9和3.9 ng mL-1，对于恩诺沙星为2.2和2.5 ng mL-1，对于沙拉沙星为3.8和7 ng mL-1，对于二氟沙星为4和4.2 ng mL-1，对于恶喹酸为2.3和4 ng mL-1，对于氟甲喹为2.7和40 ng mL-1。精密度在每种分析物的两个浓度水平上确定，并以相对标准偏差的百分比表示，其值在1.9%至7.8%之间。使用欧盟委员会的建议对样品分析的验证程序进行了实施，并计算了牛乳的决策限和检测能力。该方法应用于添加了目标分析物的全脂、半脱脂和脱脂牛奶样品，回收率在93.3%至106.0%之间。
