Department of Chemistry, College of Science, Engineering and Technology, University of South Africa, Pretoria, South Africa.
Anal Chim Acta. 2012 Jun 12;730:80-6. doi: 10.1016/j.aca.2011.11.036. Epub 2011 Dec 8.
A simple and cost effective sample pre-treatment method, dispersive liquid-liquid microextraction (DLLME), has been developed for the extraction of six fluoroquinolones (FQs) from chicken liver samples. Clean DLLME extracts were analyzed for fluoroquinolones using liquid chromatography with diode array detection (LC-DAD). Parameters such as type and volume of disperser solvent, type and volume of extraction solvent, concentration and composition of phosphoric acid in the disperser solvent and pH were optimized. Linearity in the concentration range of 30-500 μg kg(-1) was obtained with regression coefficients ranging from 0.9945 to 0.9974. Intra-day repeatability expressed as % RSD was between 4 and 7%. The recoveries determined in spiked blank chicken livers at three concentration levels (i.e. 50, 100 and 300 μg kg(-1)) ranged from 83 to 102%. LODs were between 5 and 19 μg kg(-1) while LOQs ranged between 23 and 62 μg kg(-1). All of the eight chicken liver samples obtained from the local supermarkets were found to contain at least one type of fluoroquinolone with enrofloxacin being the most commonly detected. Only one sample had four fluoroquinolone antibiotics (ciprofloxacin, difloxacin, enrofloxacin, norfloxacin). Norfloxacin which is unlicensed for use in South Africa was also detected in three of the eight chicken liver samples analyzed. The concentration levels of all FQs antibiotics in eight samples ranged from 8.8 to 35.3 μg kg(-1), values which are lower than the South African stipulated maximum residue limits (MRL).
一种简单且经济高效的样品前处理方法，分散液液微萃取（DLLME），已被开发用于从鸡肝样品中提取六种氟喹诺酮（FQs）。使用带有二极管阵列检测（LC-DAD）的液相色谱法对清洁的 DLLME 提取物进行氟喹诺酮分析。优化了分散溶剂的类型和体积、萃取溶剂的类型和体积、分散溶剂中磷酸的浓度和组成以及 pH 等参数。在 30-500μgkg(-1) 的浓度范围内获得了线性关系，回归系数范围为 0.9945 至 0.9974。在三个浓度水平（即 50、100 和 300μgkg(-1)) 测定的加标空白鸡肝中的日内重复性表示为%RSD 在 4%至 7%之间。在三个浓度水平（即 50、100 和 300μgkg(-1)) 测定的加标空白鸡肝中的回收率范围为 83%至 102%。LOD 范围为 5 至 19μgkg(-1)，LOQ 范围为 23 至 62μgkg(-1)。从当地超市获得的所有 8 个鸡肝样本均发现至少含有一种氟喹诺酮，其中恩诺沙星是最常见的检测到的。只有一个样本含有四种氟喹诺酮抗生素（环丙沙星、二氟沙星、恩诺沙星、诺氟沙星）。在分析的 8 个鸡肝样本中，有 3 个样本还检测到未在南非许可使用的诺氟沙星。在 8 个样本中，所有 FQs 抗生素的浓度水平范围为 8.8 至 35.3μgkg(-1)，低于南非规定的最大残留限量（MRL）。
