液相色谱/质谱联用同时测定饲料中六种离子载体的快速方法

Rapid method for the simultaneous determination of six ionophores in feed by liquid chromatography/mass spectrometry.

作者信息

Vudathala Daljit, Murphy Lisa

机构信息

University of Pennsylvania, School of Veterinary Medicine, Department of Pathobiology, New Bolton Center Toxicology Laboratory, 382 West St Rd, Kennett Square, PA 19348, USA.

出版信息

J AOAC Int. 2012 Jul-Aug;95(4):1016-22. doi: 10.5740/jaoacint.11-023.

DOI:10.5740/jaoacint.11-023

PMID:22970566

Abstract

A simple and highly sensitive LC/MS method was developed for the simultaneous determination of six ionophores--lasalocid, monensin, laidlomycin, maduramycin, salinomycin, and narasin--in feed. The procedure involved extraction of 1 g of feed with 4 mL of methanol-water (9 + 1, v/v) by shaking on a platform shaker for 45 min. After centrifugation, the extracts were diluted with methanol-water (75 + 25, v/v) and analyzed without any cleanup. The analysis was performed on a Betasil C18 column (150 x 4.6 mm id, 5 pm particle size) connected to an LC/MS system operated in the atmospheric pressure chemical ionization (APCI) mode. We believe this to be the first method that uses the APCI mode for the analysis of ionophores. The mobile phase consisted of 50 mM ammonium acetate as solvent A and acetonitrile-methanol (7 + 3, v/v) as solvent B in a gradient run. Excellent recoveries of 81-120% were found for all compounds at fortification levels of 1-200 microg/g, with RSD < or =15% (except 17% for maduramycin at 2 and 5 microg/g, and 16% for salinomycin at 1 microg/g). At 0.5 microg/g, recoveries of 87-119% were obtained, with RSD < or =20%. However, recovery of lasalocid was 133% and salinomycin 79% in sow and horse feed, respectively. Average RSD values of lasalocid and salinomycin were 22 and 21%, respectively. Finally, proficiency test samples analyzed with the method demonstrated favorable agreement with the certified values.

摘要

建立了一种简单且高灵敏度的液相色谱/质谱（LC/MS）方法，用于同时测定饲料中的六种离子载体——拉沙洛西、莫能菌素、莱德洛霉素、马杜霉素、盐霉素和那拉菌素。该方法包括称取1 g饲料，加入4 mL甲醇-水（9 + 1，v/v），在平台振荡器上振荡45分钟进行萃取。离心后，萃取液用甲醇-水（75 + 25，v/v）稀释，无需进一步净化即可进行分析。分析在连接到以大气压化学电离（APCI）模式运行的LC/MS系统的Betasil C18柱（150×4.6 mm内径，5μm粒径）上进行。我们认为这是第一种使用APCI模式分析离子载体的方法。流动相由50 mM醋酸铵作为溶剂A和乙腈-甲醇（7 + 3，v/v）作为溶剂B进行梯度洗脱。在1 - 200μg/g的添加水平下，所有化合物的回收率均在81% - 120%之间，相对标准偏差（RSD）≤15%（2μg/g和5μg/g的马杜霉素RSD为17%，1μg/g的盐霉素RSD为16%除外）。在0.5μg/g时，回收率为87% - 119%，RSD≤20%。然而，在母猪和马饲料中，拉沙洛西的回收率分别为133%，盐霉素的回收率分别为79%。拉沙洛西和盐霉素的平均RSD值分别为22%和21%。最后，用该方法分析的能力验证样品与认证值显示出良好的一致性。