高职食品生物化学新型实验教学体系和案例分析

构建包括基础型实验、综合型实验和设计型实验3个层次内容的食品生物化学新型实验教学体系,并依据典型案例分析,介绍如何妥善处理理论与实践、本课程与后续课程、课内与课外、教学与科研的关系。     

大气压化学电离质谱法测定饲料中的醋酸甲羟孕酮

醋酸甲羟孕酮(medroxyprogesteroneacetate)是一种人工合成生长激素,一般被用来生产避孕药及补充人体激素,但是如果使用过量,将影响生育功能。欧盟已经明令禁止在食物和饲料中使用醋酸甲羟孕酮。2002年7月德国首次发现从荷兰进口的生猪猪肉中含有该激素,深入的调查后发现欧盟成员国的猪饲料和一些软饮料里发现了禁用的醋酸甲羟孕酮,可能在欧盟继疯牛病、口蹄疫和二(口恶)英之后引发新的食品安全危机。为保证我国动物源性食品安全,维护人民身体健康,必须建立一种适用、可行、规范的残留检测方法以适应当前加入WIO的形势需要。本实验建立了高效液相色谱-质谱联用法(LC-MS)测定饲料中醋酸甲羟孕酮,旨在为政府从源头上监控饲料中的醋酸甲羟孕酮提供准确可靠的检测方法。     

饲料中八种磺胺药物的高效液相色谱测定

结合液、液分配和固相萃取,建立了同时分析食用动物饲料中磺胺嘧啶、磺胺甲基嘧啶、磺胺二甲嘧啶、磺胺甲氧哒嗪、磺胺甲基异唑、磺胺间甲氧嘧啶、磺胺间二甲氧嘧啶和磺胺喹啉8种磺胺类药物的高效液相色谱方法。比较和优化了不同的提取方法和净化参数,方法对饲料中磺胺的检出限为0.20×10-6(w),八种磺胺添加水平为1×10-6(w)时,回收率在68%以上,相对标准偏差小于12%。     

高效液相色谱法测定饲料中辛硫磷残留量

提出了高效液相色谱法测定饲料中辛硫磷残留量的方法。样品经乙酸乙酯提取,氨基固相萃取小柱净化,所得净化液以反相C18色谱柱为分离柱,以乙腈-水(65+35)混合溶液为流动相,在检测波长280nm处进行测定。辛硫磷的质量浓度与其峰面积在0.10～0.50mg·L-1范围内呈线性关系,方法的检出限(3S/N)为0.10mg·kg-1。加标回收率在80.0%～88.2%之间,测定值的相对标准偏差(n=5)在1.6%～6.5%之间。     

Biofouling in spiral wound membrane systems: Three-dimensional CFD model based evaluation of experimental data

A three-dimensional (3D) computational model describing fluid dynamics and biofouling of feed channels of spiral wound reverse osmosis and nanofiltration membrane systems was developed based on results from practice and experimental studies. In the model simulations the same feed spacer geometry as applied in practice and the experimental studies was used. The 3D mathematical model showed the same trends for (i) feed channel pressure drop, (ii) biomass accumulation, (iii) velocity distribution profile, resulting in regions of low and high liquid flow velocity also named channeling. The numerical model predicted a dominant biomass growth on the feed spacer, consistent with direct in situ observations on biofouling of spiral wound membrane modules and monitors using Magnetic Resonance Imaging (MRI). The model confirms experimental results that feed spacer fouling is more important than membrane fouling. The paper shows that mathematical modeling techniques have evolved to a stage that they can be used hand-in-hand with experiments to understand the processes involved in membrane fouling.