Jacobsen Anne Marie, Halling-Sørensen Bent
Department of Pharmaceutical and Analytical Chemistry, The Danish University of Pharmaceutical Sciences, 2 Universitetsparken, 2100 Copenhagen, Denmark.
Anal Bioanal Chem. 2006 Mar;384(5):1164-74. doi: 10.1007/s00216-005-0261-9. Epub 2006 Feb 17.
A multi-component method focussing on thorough sample preparation has been developed for simultaneous analysis of swine manure for three classes of antibiotic-tetracyclines, sulfonamides, and tylosin. Liquid manure was initially freeze-dried and homogenised by pulverization before extraction by pressurised liquid extraction. The extraction was performed at 75 degrees C and 2,500 psig in three steps using two cycles with 0.2 mol L(-1) citric acid buffer (pH 4.7) and one cycle with a mixture of 80% methanol with 0.2 mol L(-1) citric acid (pH 3). After liquid-liquid extraction with heptane to remove lipids, the pH of the manure was adjusted to 3 with formic acid and the sample was vacuum-filtered through 0.6 mum glass-fibre filters. Finally the samples were pre-concentrated by tandem SPE (SAX-HLB). Recoveries were determined for manure samples spiked at three concentrations (50-5,000 microg kg(-1) dry matter); quantification was achieved by matrix-matched calibration. Recoveries were >70% except for oxytetracycline (42-54%), sulfadiazine (59-73%), and tylosin (9-35%) and did not vary with concentration or from day-to-day. Limits of quantification (LOQ) for all compounds, determined as a signal-to-noise ratio of 10, were in the range 10-100 microg kg(-1) dry matter. The suitability of the method was assessed by analysis of swine manure samples from six different pig-production sites, e.g. finishing pigs, sows, or mixed production. Residues of antibiotics were detected in all samples. The largest amounts were found for tetracyclines (up to 30 mg kg(-1) dry matter for the sum of CTC and ECTC). Sulfonamides were detected at concentrations up to 2 mg kg(-1) dry matter (SDZ); tylosin was not detected in any samples.
已开发出一种多组分方法，该方法着重于进行彻底的样品制备，用于同时分析猪粪中的三类抗生素——四环素、磺胺类药物和泰乐菌素。液体猪粪首先进行冷冻干燥，然后通过粉碎使其均匀化，再进行加压液体萃取。萃取在75摄氏度和2500磅力/平方英寸的压力下分三步进行，使用两个循环的0.2摩尔/升柠檬酸缓冲液（pH 4.7）和一个循环的80%甲醇与0.2摩尔/升柠檬酸（pH 3）的混合物。用庚烷进行液液萃取以去除脂质后，用甲酸将猪粪的pH值调至3，然后将样品通过0.6微米的玻璃纤维滤器进行真空过滤。最后，样品通过串联固相萃取（SAX - HLB）进行预浓缩。测定了添加三种浓度（50 - 5000微克/千克干物质）的猪粪样品的回收率；通过基质匹配校准实现定量。除土霉素（42 - 54%）、磺胺嘧啶（59 - 73%）和泰乐菌素（9 - 35%）外，回收率均>70%，且回收率不随浓度或每日变化而变化。所有化合物的定量限（LOQ），以信噪比为10确定，范围为10 - 100微克/千克干物质。通过分析来自六个不同养猪场（如育肥猪、母猪或混合养殖）的猪粪样品来评估该方法的适用性。在所有样品中均检测到抗生素残留。四环素的含量最高（土霉素和差向土霉素总量高达30毫克/千克干物质）。磺胺类药物的检测浓度高达2毫克/千克干物质（磺胺嘧啶）；在任何样品中均未检测到泰乐菌素。
