Liang Chengzhu

液相色谱-四极杆/飞行时间高分辨质谱组合化学计量学方法快速筛查婴幼儿配方乳粉中化学危害物

采用液相色谱-四极杆/飞行时间(LC-Triple TOF ® )高分辨质谱组合化学计量学方法建立了婴幼儿配方乳粉中化学危害物的快速筛查模型。实验采用人工添加外源化学物质(沙丁胺醇、林可霉素、磺胺嘧啶、螺旋霉素、双氯西林和醋酸甲地孕酮)模拟婴幼儿配方乳粉中未知化学危害物污染,15种不同的乳粉等量混合后用水复溶,配制代表性乳粉溶液样品。依据添加与否将样品分为参照组(不含添加的化合物)和添加组。乳粉溶液试样加入乙腈进行提取,经Captiva ND Lipids 固相萃取柱净化,CORTECS TM UPLC C 18+ 柱液相色谱分离,以0.3%(v/v)甲酸-5%(v/v)水-乙腈溶液和0.3%(v/v)甲酸-5%(v/v)乙腈-水溶液为流动相梯度洗脱;飞行时间质谱全扫描(TOF MS)-信息依赖性采集(IDA)-子离子扫描(product ion scan)正离子模式采集样品数据。数据经MarkerView TM 软件预处理后导入SIMCA-P软件,对比分析参照组和添加组样品数据,拟合构建正交偏最小二乘法-判别分析(OPLS-DA)模型,并利用此模型进行样品组别区分和添加化合物识别。结果表明,实验构建的筛查模型拟合度和预测能力良好( R 2 X (cum)=0.742, R 2 Y (cum)=0.997, Q 2 Y (cum)=0.905),参照组和添加组样品被显著区分,6种添加的化合物(最低添加水平为50 μg/kg,以乳粉计)全部被可靠地识别。该研究建立的方法为婴幼儿配方乳粉质量安全主动分析监控体系提供了有益技术参考。

The development of a diagnostic gene chip for detecting five kinds of viruses in horses

The highly conserved DNAs of Equine herpesvirus 1(EHV1), Equine arteritis virus(EAV), Equine influenza virus(EIV), Equine infectious anaemia virus (EIAV) and Eastern equine encephalomyelitis virus (EEEV) were acquired by molecular cloning, and then spotted on the treated glass slides as the diagnostic gene-chip. And the cDNAs reverse-transcripted from RNAs of samples were labeled with Cy5 fluorescence as probes. Following specific hybridization of deposited gene chip and labeled probes, fluorescence signals were scanned by laser scanner and the obtained image was analyzed by QiamtArray software with the digital computer. The results showed that the prepared gene chip could detect and distinguish the five equine viruses. And its sensitivity was about 25 copies of viral genomes. The hybridization specificity was confirmed by the presence of red fluorescence signals on the corresponding sites with samples from the five relevant viruses in horses and by the absence of positive signals with the specimens from irrelevant viruses in other animals. Peripheral blood leucocyte (PBL) from some seropositive horses of post-arrival quarantine was negative by virus isolation but positive for EHV1 and EAV by gene chip. The evidence suggests that gene chip, which is quick, specific, sensitive, and reliable, can provide a practical alternative to screen and quarantine a large number of samples within a very short period of time.