肉质食品中痕量瘦肉精成分的快速检测对食品的质量控制与安全保障具有重要的意义。本文采用瘦猪肉、肥猪肉、猪肺、牛肉、火腿肠、猪心、熏猪蹄及腊肉等为代表性样品,以自行研制的内部萃取电喷雾电离质谱(i EESI-MS)技术为基础,在正离子检测模式下,选择甲醇水(V/V 35/65)作萃取剂,在无需任何样品预处理的条件下对样品进行直接质谱分析,获得了样品在m/z 50-1000范围内的化学指纹谱图,并对谱图中瘦肉精成分疑似物的目标离子进行碰撞诱导解离(CID)实验,通过特征碎片离子排除假阳性,实现了样品中痕量瘦肉精成分的快速高通量筛查。实验表明,i EESI-MS可快速检测到猪肉样品中克伦特罗(Clenbuterol)、丙卡特罗(Procaterol)等瘦肉精成分,单个样品分析时间少于1 min,样品耗量低于100 mg,具有操作简便、分析速度快等优点,为肉类产品的质量控制与安全保障提供了新方法。
Rapid detection of trace levels of β-agonists in meat samples plays an important role in the quality and safety control of meat products. In this study, meat samples, including lean pork, fat pork, pig lung, beef, ham sausage, pig heart, smoked pig feet, and bacon were used as representative samples and were directly analyzed using a homemade internal extractive electrospray ionization(i EESI) source coupled with an LTQ mass spectrometer(MS) under the positive ion detection model. Methanol/water(V/V, 35/65) was selected as the extracting agent; no pretreatment was conducted on the samples, and the mass spectra for chemical fingerprints within an m/z range of 50–1000 were obtained. The collision-induced dissociation(CID) experiments were carried out on the target ions suspected to be "β-agonists". False positive results were avoided by comparing the characteristic fragment ions with the literature, and a high-throughput screening was performed for traces of β-agonists in meat samples. The results demonstrated that i EESI-MS could rapidly detect clenbuterol, procaterol, and other β-agonists in pork samples; the duration of single sample analysis was less than one minute, and the amount of sample consumed was less than 100 mg. This method has the advantages of simple operation and rapid analysis, and provides a new approach for the quality and safety control of meat products.