UPLC-MS-MS法测定饲料、原料乳及乳制品中3 种氯霉素类药物残留

建立超高效液相色谱-质谱联用法检测饲料、牛乳及广义乳制品中氯霉素类药物残留的通用检测方法。研究适用于检测饲料、原料乳、液体乳、发酵乳、含乳饮料、乳粉、奶片、冷冻饮品中氯霉素类药物的前处理方法以及适用的超高效液相色谱及质谱条件。样品经低温冷冻沉淀蛋白质后，乙腈提取，饱和氯化钠使乙腈、水分层，取上清液氮气吹干定容后，正己烷除脂，乙腈、水梯度洗脱，电喷雾负离子多反应监测模式进行检测。氯霉素、甲砜霉素、氟甲砜霉素定量限0.1 μg/kg。氯霉素类药物添加范围0.1～2.5 μg/kg时，基质效应为57.9%～139.2%，回收率为64.3%～120.2%，相对标准偏差为2.1%～10.0%。该方法具有简单方便、检测周期短、适用于更广泛样品检测的特点。

Determination of Chloramphenicol,Thiamphenicol and Florfenicol Residues in Feed,Raw Milk andDairy Products by UPLC-MS-MS

An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method for
simultaneous determination of chloramphenicol, thiamphenicol and florfenicol residues in feed, raw milk and dairy products
was developed. The extraction procedures and the UPLC-MS-MS conditions for feed, raw milk, liquid milk, fermented milk,
milk drinks, milk powder, milk tablet and frozen drinks were studied. After protein in samples was precipitated by cooling
down, the compounds were extracted into acetonitrile, which was separated into layers in the presence of added saturated
sodium chloride. The supernatant was dried under nitrogen, and then re-dissolved before the removal of fat by addition of
n-hexane. The compounds were analyzed in a negative electrospray ion multiple reaction monitoring mode with a mobile
phase composed of acetonitrile and water by means of gradient elution. The limit of quantification (LOQ) was 0.1 μg/kg
for chloramphenicol, thiamphenicol and florfenicol. The matrix effects, recovery rates, and relative standard deviation
(RSD) were 57.9%–139.2%, 64.3%–120.2% and 2.1%–10.0%, at fortification levels of 0.1–2.5 μg/kg for chloramphenicol,
thiamphenicol and florfenicol, respectively. This method is simple, convenient, fast and suitable for the quantification and
confirmation of chloramphenicol, thiamphenicol, and florfenicol in feed, milk and dairy products.