Division of Foods, National Institute of Health Sciences, Tonomachi 3-25-26, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan.
Division of Foods, National Institute of Health Sciences, Tonomachi 3-25-26, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan.
J Chromatogr B Analyt Technol Biomed Life Sci. 2019 Mar 1;1109:37-44. doi: 10.1016/j.jchromb.2019.01.018. Epub 2019 Jan 26.
A reliable liquid chromatography-tandem mass spectrometry method was developed to determine total florfenicol residues in bovine tissues and eel. Florfenicol and its metabolites (florfenicol amine, monochloroflorfenicol, florfenicol oxamic acid, and florfenicol alcohol) were analyzed as the marker residue, florfenicol amine, as defined by several regulatory agencies. After hydrolysis with hydrochloric acid, samples were defatted and subjected to solid-supported liquid extraction and Oasis MCX-cartridge cleanup before analysis. The method was validated for florfenicol and its metabolites at two levels in eel and bovine muscle, fat, and liver. Excellent recoveries were obtained (93-104%), with relative standard deviations of <6% for all compounds. Negligible matrix effects and minimal analyte loss during sample preparation enabled accurate quantification by external calibration using solvent standards. No interfering peaks were observed around the retention time of florfenicol amine, indicating the high selectivity of the method. Retention times in the spiked samples corresponding to that of the calibration standard in solvent did not exceed ±0.1 min. Ion ratios from the spiked sample were within ±10% (relative) of the calibration standards. Calibration curves were linear in the range of 0.5 to 100 ng/mL, with coefficients of determination higher than 0.998. The limits of quantification and limits of detection of the proposed method were estimated to be 0.01 mg/kg and 0.0005 mg/kg, respectively, in all food samples. Thus, the developed method is considered reliable and suitable for regulatory use.
建立了一种可靠的液相色谱-串联质谱法，用于测定牛组织和鳗鱼中总氟苯尼考残留量。氟苯尼考及其代谢物（氟苯尼考胺、单氯氟苯尼考、氟苯尼考肟酸和氟苯尼考醇）被分析为标记残留物，如几个监管机构所定义的氟苯尼考胺。样品经盐酸水解后，用固相萃取和 Oasis MCX 小柱净化进行脱脂，然后进行分析。该方法在鳗鱼和牛肌肉、脂肪和肝脏中对氟苯尼考及其代谢物在两个水平上进行了验证。所有化合物的回收率均在 93-104%之间，相对标准偏差均<6%。基质效应可忽略不计，样品制备过程中分析物损失最小，通过使用溶剂标准进行外标法定量可实现准确定量。在氟苯尼考胺的保留时间附近未观察到干扰峰，表明该方法具有高选择性。在加标样品中的保留时间与溶剂中校准标准的保留时间相差不超过±0.1 min。加标样品的离子比与校准标准的离子比相差在±10%（相对）以内。校准曲线在 0.5 至 100 ng/mL 范围内呈线性，相关系数均高于 0.998。所提出方法的定量限和检测限估计分别为所有食品样品中的 0.01 mg/kg 和 0.0005 mg/kg。因此，该方法被认为是可靠的，适合监管使用。
