Nitrofuran antibiotic residues in pork: The FoodBRAND retail survey

Use of nitrofuran drugs in food-producing animals has been prohibited within the EU because they may represent a public health risk. Monitoring compliance with the ban has focused on the detection of protein-bound nitrofuran metabolites which, in contrast to the parent compounds, are stable and persist in animal tissues. As part of the “FoodBRAND” project, an extensive survey of pork was undertaken across 15 European countries. Samples (n = 1500) purchased at retail outlets were analysed for the nitrofuran metabolites AOZ, AMOZ, AHD and SEM using LC–MS/MS determination of nitrobenzaldehyde derivatives. Limits of quantification for the method were 0.1 μg/kg (AOZ, AMOZ), 0.2 μg/kg (SEM) and 0.5 μg/kg (AHD). Of the 1500 samples tested, measurable residues of nitrofuran metabolites were confirmed in 12 samples (0.8% incidence overall) of which 10 samples were purchased in Portugal (AOZ, 0.3 μg/kg; AMOZ, 0.2–0.6 μg/kg) and one sample each in Italy (AMOZ, 1.0 μg/kg) and Greece (AOZ, 3.0 μg/kg).     

气相色谱-质谱法测定猪肉中盐酸克伦特罗残留量

按NY/T 468-2006所述方法在碱性条件下,用乙酸乙酯提取和用盐酸溶液反萃取制得含有盐酸克伦特罗的试样溶液,调节溶液的酸度至pH 4.5后,经SCX固相萃取柱净化。在经净化后的试液中加入1.6mg·L-1美托洛尔溶液40μL作为内标。将溶液置于60℃水浴中吹氮蒸干,加入甲苯200μL和BSTFA衍生试剂100μL,于80℃烘箱中衍生1h。冷却后再加甲苯200μL,经DB-5MS毛细管柱分离,在SIM模式下进行MS测定,选择监测离子为m/z86(定量离子)和m/z262,243,187(定性离子)。内标法定量。盐酸克伦特罗的线性范围为16~512μg·L-1,其检出限(3S/N)为1.0μg·kg-1。以空白样品为基体进行加标回收试验,测得回收率在79.7%~86.6%之间,测定值的相对标准偏差(n=6)在4.8%~6.7%之间。     

反相液相色谱-串联质谱法检测猪肝中26种β2-受体激动剂类药物残留

建立了一种猪肝中26种β2-受体激动剂药物残留的反相液相色谱-串联质谱(HPLC-MS/MS)检测方法。样品经β-葡萄糖苷酸酶/芳基硫酸酯酶酶解12 h后,加入HClO4调至pH 1,去除蛋白,残渣经过0.1 mol/L HClO4再次提取后,合并提取液,调节混合提取液至pH 4,过混合阳离子(MCX)固相萃取柱净化。采用0.1%甲酸(A)和0.1%甲酸-乙腈(B)作为流动相进行梯度洗脱,质谱(ESI+)采用多离子检测模式(MRM)对β2-受体激动剂的定量离子和定性离子进行监测,本方法在15 min内完成26种目标化合物的分离分析。26种β2-受体激动剂在5、10和20μg/L添加水平的回收率为64.0%~112.7%,相对标准偏差小于15.2%,方法检出限为0.15~1.35μg/kg。     

超高效液相色谱-串联质谱法鉴定猪肉的特异性肽生物标志物

以亲缘关系较近的猪、牛和羊3个物种的肌肉组织为研究对象,采用超高效液相色谱-串联质谱(UPLC-MS),筛选并确认了猪物种肉特异性肽生物标志物.3种纯肉样品经蛋白质提取、胰蛋白酶消化和UPLC-TripleTOF-MS分离鉴定,得到的总离子流图谱(TIC)与Uniprot蛋白质数据库对比分析,筛选出3个物种肉的3种高丰度同源蛋白和8种潜在的肽生物标志物;潜在的肽生物标志物经QTRAP-MS质谱的多反应模式(MRM)分析,最终确认了猪物种肉的5种肽生物标志物,其中3种肽生物标志物未见文献报道.     

分子印迹柱-高效液相色谱法测定猪肉中磺胺嘧啶(英文)

建立了分子印迹柱-高效液相色谱法检测猪肉中磺胺嘧啶残留方法。制备了磺胺嘧啶的分子印迹柱,并优化了分子印迹柱的萃取条件。研究结果表明,在最佳萃取条件下,分子印迹柱-高效液相色谱法的加标回收率≥75.6%,相对标准偏差≤6.1%。分子印迹柱为固相萃取柱可以预浓缩与纯化猪肉样品中磺胺嘧啶。与氧化铝萃取柱比,分子印迹柱具有较好的重复性和萃取效率。本方法已成功用于实际猪肉样品中磺胺嘧啶含量的检测,结果满意。     

化学发光酶免疫法检测猪肉中氯丙嗪残留

采用棋盘滴定法确定包被抗原浓度和抗体稀释倍数,通过单因素实验优化了竞争反应时间、磷酸盐缓冲液浓度、甲醇含量、pH值等参数,建立了氯丙嗪的间接竞争化学发光酶免疫检测方法,并考察了方法的特异性、灵敏度和稳定性.结果表明,最佳反应条件为包被抗原浓度为0.05 μg/L;氯丙嗪抗体稀释32000倍;体系缓冲液为含10％甲醇、0.1 mol/L磷酸盐缓冲液(pH 7.0).本方法的IC50为0.12 μg/L;检出限为0.02 μg/L;线性范围0.02～24.78 μg/L;批内和批间相对标准偏差均小于10％.与其它结构类似物没有明显交叉反应.猪肉检测的平均回收率为87.4％～105.6％,与高效液相色谱方法的相关性良好.本方法具有较高的灵敏度和较好的稳定性.     

高效液相色谱-串联质谱测定猪肉中3种β-受体激动剂残留量

建立一种同时测定猪肉中3种β-受体激动剂残留量的高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)确证分析方法。样品经β-葡萄糖醛酸酶/芳基硫酸酯酶酶解、乙酸铵缓冲液提取和MCX固相萃取柱净化,采用Agilent ZorbaxSB-C18(2.1mm×150mm,3.5μm)色谱柱,0.1%的甲酸水溶液、甲醇和乙腈作为流动相进行洗脱,高效液相色谱分离,电喷雾离子源电离,正离子多反应监测模式进行检测,内标法定量。3种药物在0.05～1μg/kg浓度范围内线性良好,相关系数r均大于0.999,0.05、0.1、0.5μg/kg3个浓度水平的添加回收率在89.7%～106.7%之间,相对标准偏差为2.4%～8.6%,3种药物的定量限均为0.05μg/kg。方法适用于猪肉中β-受体激动剂残留的确证分析。     

Analytical procedure to simultaneously measure trace amounts of trenbolone acetate and beta-trenbolone residues in porcine muscle using HPLC-UVD and MS

The current study was undertaken to validate the performance for the determination of both TBA and beta-trenbolone (beta-TB) residues in porcine muscle at concentrations required to monitor compliance with the maximum residue limit (MRL). The method involves a one phase liquid-liquid extraction, cleanup with low-temperature fat precipitation, separation of the respective compounds by HPLC on a Capcell pak C(18) column, use of a methanol-water isocratic system as an eluent, and measurement by UV absorbance detection at 340 nm. Both compounds were confirmed using LC-MS/MS with electrospray interface (ESI) and a triple quadrupole (QqQ) analyzer. The method was found to be precise and accurate, with a linearity range of 1-10 microg/kg (r(2) >0.973). The intra- and interday precision showed good reproducibility with RSDs < or =13.25%. The LODs were 0.12 and 0.22 microg/kg, and the LOQs were 0.37 and 0.66 microg/kg, for TBA and beta-TB, respectively. The applicability of the method was demonstrated by analyzing real samples collected from major cities in the Republic of Korea. No residues of the selected compounds were detected in any of the samples. The advantages of our method are that it is: selective, sensitive, requires a short time for analysis (13 min), and performs simple sample extraction and clean-up procedure with low-temperature fat precipitation as compared to the previously published methods.     

基于Adaboost+OLDA和近红外光谱的猪肉贮藏时间辨别

猪肉的贮藏时间和猪肉的新鲜度紧密相关。通过近红外漫反射光谱技术获取猪肉样本数据,利用正交线性判别分析(OLDA)算法进行特征提取,同时将自适应提升法(Adaboost)引入OLDA,提出了一种基于Adaboost和OLDA的集成学习算法——Adaboost+OLDA。实验针对分类正确率和运算时间将传统特征提取算法(PCA+LDA和OLDA)和Adaboost+OLDA算法进行了对比研究,结果表明Adaboost+OLDA算法不仅具有很好的运算效率,而且提高了OLDA算法的泛化能力,在猪肉样本测试中达到了95%以上的分类正确率。     

氯霉素类兽药的三甲基硅衍生物的质谱特征及其残留测定

氯霉素(chloramphenicol,CAP)是20世纪50年代开发出来的一种广谱抗生素,因其对人体具有严重毒副作用而被禁止在食用动物源产品上使用。甲砜霉素(thiamphenicol,TAP)是人工合成的氯霉素类抗生素,结构与CAP类似,毒性较CAP小,但美国等发达国家也已禁止在食用动物上使用。氟甲砜(氯