College of Food Science and Technology, Shanghai Ocean University, No. 999 Hucheng Huan Road, LinGang New City, Shanghai, China 201306.
J Agric Food Chem. 2011 Sep 28;59(18):10023-7. doi: 10.1021/jf202581k. Epub 2011 Sep 1.
Ractopamine is approved for use in swine to improve carcass leanness in the United States, but banned in the European Union and China because ractopamine residue may pose health risks. This study investigated the possibility of applying surface-enhanced Raman spectroscopy (SERS) for analysis of ractopamine in swine urine. Ractopamine (0.1-10 μg mL(-1)) was added to urine samples collected from 20 swine to prepare a total of 240 samples. A simple centrifugation, a liquid-liquid extraction (LLE) method, and a more complicated method involving liquid-liquid extraction and solid-phase extraction (LLE-SPE) were used to extract ractopamine from urine samples. Principal component analysis (PCA) and partial least-squares (PLS) regression were used for spectral data analyses. Although no satisfactory result was obtained with the centrifugation method, ractopamine could be detected at levels of 0.8 and 0.4 μg mL(-1) with the LLE and LLE-SPE extraction methods, respectively. The R2 of the PLS model of actual ractopamine values versus predicted values was 0.74 for the LLE method and 0.73 for the LLE-SPE method. The SERS method with simple sample preparation has great potential for rapid analysis of ractopamine in swine urine.
莱克多巴胺在美国被批准用于猪，以提高胴体瘦肉率，但在欧盟和中国被禁止，因为莱克多巴胺残留可能带来健康风险。本研究探讨了表面增强拉曼光谱（SERS）分析猪尿中莱克多巴胺的可能性。将莱克多巴胺（0.1-10μgmL（-1））添加到从 20 头猪采集的尿液样本中，共制备了 240 个样本。采用简单离心、液液萃取（LLE）法和更复杂的液液萃取和固相萃取（LLE-SPE）法从尿液样本中提取莱克多巴胺。采用主成分分析（PCA）和偏最小二乘（PLS）回归对光谱数据进行分析。尽管离心法没有得到满意的结果，但LLE 和 LLE-SPE 提取方法可分别检测到 0.8 和 0.4μgmL（-1）的莱克多巴胺。LLE 法的 PLS 模型实际莱克多巴胺值与预测值的 R2为 0.74，LLE-SPE 法为 0.73。该研究表明，采用简单的样品制备方法的 SERS 法具有快速分析猪尿中莱克多巴胺的巨大潜力。
