液相色谱/热喷雾质谱法测定和确证牛乳和牛肝中吡利霉素残留量的实验室间研究

Determination and confirmation of pirlimycin residue in bovine milk and liver by liquid chromatography/thermospray mass spectrometry: interlaboratory study.

作者信息

Heller D N

机构信息

U. S. Food and Drug Administration, Center for Veterinary Medicine, Beltsville, MD 20705, USA.

出版信息

J AOAC Int. 1996 Sep-Oct;79(5):1054-61.

PMID:8823914

Abstract

Three laboratories participated in trials of methods to determine and confirm pirlimycin residue in bovine milk and liver. The methods used liquid chromatography/thermospray mass spectrometry (LC/MS) with an internal standard to measure residue concentration. The internal standard was isopirlimycin, a stereoisomer of pirlimycin, which was resolved chromatographically. Determinative procedures were validated by replicate analyses of negative control, fortified control, and residue-incurred milk. For the milk method, average corrected recoveries (and coefficients of variation, CVs) were 83-113% (CV, 7.5-15.4%) at 0.2 ppm, 91-98% (CV, 3.4-18.5%) at 0.4 ppm, and 89-102% (CV, 8.8-22.9%) at 0.8 ppm. For the liver method, average corrected recoveries were 94-103% (CV, 2.2-7.1%) at 0.25 ppm, 87-94% (CV, 4.8-10.3%) at 0.5 ppm, and 96-101% (CV, 5.5-6.9%) at 1.0 ppm. There were no interferences in control samples of either matrix. Pirlimycin was confirmed by matching the retention time and relative abundances of 4 ions from sample extracts to corresponding values obtained for pirlimycin standard. Pirlimycin was confirmed in all residue-incurred samples and all samples fortified at regulatory tolerances (0.4 ppm in milk and 0.5 ppm in liver) by 2 of the 3 laboratories and in most samples by the third laboratory.

摘要

三个实验室参与了测定和确认牛乳及肝脏中吡利霉素残留量方法的试验。这些方法采用液相色谱/热喷雾质谱联用仪（LC/MS）并以内标物来测量残留浓度。内标物为异吡利霉素，它是吡利霉素的一种立体异构体，可通过色谱法分离。通过对阴性对照、加标对照以及含有残留的牛奶进行重复分析来验证测定程序。对于牛奶检测方法，在0.2 ppm时平均校正回收率（及变异系数，CV）为83 - 113%（CV，7.5 - 15.4%），在0.4 ppm时为91 - 98%（CV，3.4 - 18.5%），在0.8 ppm时为89 - 102%（CV，8.8 - 22.9%）。对于肝脏检测方法，在0.25 ppm时平均校正回收率为94 - 103%（CV，2.2 - 7.1%），在0.5 ppm时为87 - 94%（CV，4.8 - 10.3%），在1.0 ppm时为96 - 101%（CV，5.5 - 6.9%）。两种基质的对照样品均无干扰。通过将样品提取物中4种离子的保留时间和相对丰度与吡利霉素标准品对应的数值进行匹配来确认吡利霉素。三个实验室中有两个实验室在所有含有残留的样品以及所有按照监管限量（牛奶中0.4 ppm，肝脏中0.5 ppm）加标的样品中确认了吡利霉素，第三个实验室在大多数样品中也确认了吡利霉素。