Doherty S J, Fox A, Fink D W
Merck Research Laboratories, West Point, PA 19486-004, USA.
J AOAC Int. 1998 Jul-Aug;81(4):869-72.
An analytical method for determining ivermectin in feed at 0.50-3 ppm is presented. The method is based on liquid chromatographic measurement after sample preparation by adsorption chromatography on alumina and solid-phase extraction. Two complete, final, finished medicated feeds and the corresponding control feeds used in their preparation were analyzed. Recoveries from feeds fortified at 50-150% of the 2 ppm ivermectin use concentration also were determined. Mean recoveries from replicate analyses ranged from 90 to 100%, and coefficients of variation (CVs) were less than 4.5%. No significant interferences were found in control feeds. The pooled distribution of individual analytical results (n = 100) gave a mean recovery of 100%, a recovery range of 90-111%, and an overall CV of 5.5%. Resolution of the total variance into its 2 components gave a within-laboratory CV of 4.1% and a between-laboratory CV of 3.4%. There was no significant difference in recoveries among laboratories, days, concentrations, and feed base or between fortified and medicated feeds (P > 0.2).
本文介绍了一种测定饲料中伊维菌素含量的分析方法，测定范围为0.50 - 3 ppm。该方法基于在氧化铝上进行吸附色谱和固相萃取的样品制备后进行液相色谱测定。分析了两种完整、最终、已制成的加药饲料以及制备过程中使用的相应对照饲料。还测定了在伊维菌素使用浓度2 ppm的50 - 150%水平下加标饲料的回收率。重复分析的平均回收率在90%至100%之间，变异系数（CV）小于4.5%。在对照饲料中未发现明显干扰。100个单独分析结果的合并分布给出了平均回收率100%，回收率范围为90 - 111%，总体CV为5.5%。将总方差分解为两个成分，得到实验室内CV为4.1%，实验室间CV为3.4%。不同实验室、日期、浓度、饲料基质之间以及加标饲料和加药饲料之间的回收率没有显著差异（P > 0.2）。
