Hernández-Mesa Maykel, Carbonell-Rozas Laura, Cruces-Blanco Carmen, García-Campaña Ana M
Department of Analytical Chemistry, Faculty of Sciences, University of Granada,Av. Fuentenueva s/n, E-18071 Granada, Spain.
Department of Analytical Chemistry, Faculty of Sciences, University of Granada,Av. Fuentenueva s/n, E-18071 Granada, Spain.
J Chromatogr B Analyt Technol Biomed Life Sci. 2017 Nov 15;1068-1069:125-130. doi: 10.1016/j.jchromb.2017.10.016. Epub 2017 Oct 13.
A novel salting-out assisted liquid-liquid extraction (SALLE) method has been developed for the extraction of eight 5-NDZ antibiotics from milk samples prior to their analysis by UHPLC. An exhaustive study of the parameters involved in the SALLE procedure has been carried out, optimizing the extraction solvent volume, the amount of the salt agent, and the centrifugation and vortex timing by an experimental design. After sample treatment, the obtained extract was reconstituted in the mobile phase (6:94 (v/v) acetonitrile/water containing 0.1% (v/v) of formic acid) and analyzed by the proposed UHPLC-UV method. Separation was accomplished in a C18 Zorbax Eclipse Plus (50mm×2.1mm, 1.8μm) column at 45°C within 8min. Gradient mode was considered using a mobile phase consisting of 0.1% (v/v) formic acid aqueous solution and acetonitrile containing 0.1% (v/v) formic acid at a flow rate of 0.45mL/min. Analytical signals were monitored at 320nm. Matrix-matched calibration curves showed satisfactory linearity (R≥0.996). LODs, ranging from 2 to 4μg/L, were achieved and precision studies showed RSDs lower than 12.8% in terms of peak height. Additionally, recoveries higher than 62.8% were obtained for all studied compounds in milk samples.
已开发出一种新型盐析辅助液液萃取（SALLE）方法，用于在通过超高效液相色谱（UHPLC）分析之前从牛奶样品中萃取8种5-硝基咪唑类抗生素。对SALLE程序中涉及的参数进行了详尽研究，通过实验设计优化了萃取溶剂体积、盐试剂用量、离心和涡旋时间。样品处理后，将所得萃取物在流动相（6:94（v/v）乙腈/水，含0.1%（v/v）甲酸）中复溶，并通过所提出的UHPLC-UV方法进行分析。在C18 Zorbax Eclipse Plus（50mm×2.1mm，1.8μm）色谱柱上于45°C在8分钟内完成分离。采用梯度模式，流动相由0.1%（v/v）甲酸水溶液和含0.1%（v/v）甲酸的乙腈组成，流速为0.45mL/min。在320nm处监测分析信号。基质匹配校准曲线显示出令人满意的线性（R≥0.996）。实现了2至4μg/L的检测限，精密度研究表明，就峰高而言，相对标准偏差（RSD）低于12.8%。此外，在牛奶样品中，所有研究化合物的回收率均高于62.8%。
