亲水作用色谱-电喷雾串联质谱法测定水产品中的氟苯尼考胺的残留量

建立亲水作用色谱-电喷雾串联质谱测定水产品中氟苯尼考胺残留量的测定方法。样品用碱性乙酸乙酯提取,以正己烷和脂肪吸附材料去除油脂,用5 mmol/L乙酸铵溶液(含0.2%甲酸)和乙腈作为流动相,以梯度洗脱方式在Acquity UPLC BEH HILIC柱(55 mm×2.1 mm,1.7μm)色谱柱上分离,以电喷雾离子源正离子模式进行质谱分析,基质外标法定量。结果表明,氟苯尼考胺的质量浓度在0.1~20μg/L范围内呈良好的线性,相关系数(r2)大于0.990。在1.0~50.0μg/kg加标水平下,虾、黄鱼、鳗鱼、烤鳗的平均回收率为70.5%~87.7%,相对标准偏差为4.8%~11.6%,定量限为1.0μg/kg。该方法简单、灵敏、稳定,可满足水产品中氟苯尼考胺残留量的检测和确证需要。     

Simultaneous determination of 3,4-dihydroxyphenylacetic acid, uric acid and ascorbic acid by poly(L-arginine)/multi-walled carbon nanotubes composite film

The poly(L-Arginine)(PArg)-multiwalled carbon nanotubes (MWCNTs) composite film was used to modify glassy carbon electrode (GCE) to fabricate PArg/MWCNTs/GCE through electropolymerization of L-Arginine on MWCNTs/GCE. The PArg/MWCNTs/GCE exhibited high electro-catalytic activities towards the oxidation of 3,4-dihydroxyphenylacetic acid (DOPAC), uric acid (UA), and ascorbic acid (AA), and could be sensitively used for simultaneous determination of DOPAC, AA, and UA in pH 7.4 phosphate-buffered solution (PBS).The linear ranges were 7 microM to 2.7 mM for DOPAC, 3 microM to 1.2 mM for UA, and 70 microM to 1.4 mM for AA. The detection limits were 1.3 microM for DOPAC, 0.7 microM for UA and 20 microM for AA.     

A method of workflow scheduling based on colored Petri nets

Effective methods of workflow scheduling can improve the performance of workflow systems. Based on the study of existing scheduling methods, a method of workflow scheduling, called phased method, is proposed. This method is based on colored Petri nets. Activities of workflows are divided into several groups to be scheduled in different phases using this method. Details of the method are discussed. Experimental results show that the proposed method can deal with the uncertainties and the dynamic circumstances very well and a satisfactory balance can be achieved between static global optimization and dynamic local optimization.     

带宽标准物质的定值和不确定度的评定

标准物质的定值是研制标准物质过程中的重要环节。带宽标准物质的定值过程采用多家实验室协同定值的方法。本文以纳米二氧化钛带宽标准物质为例,对带宽标准物质的定值过程及不确定度评定进行了详细介绍。     

体外模拟胃肠消化过程中云南金花茶抗氧化能力变化

为探究云南金花茶在消化过程中总黄酮、总多酚释放及功能活性的变化情况,该研究采用体外模拟胃肠消化模型测定了云南金花茶消化液中总黄酮、总多酚浓度及自由基清除能力、铁离子还原能力和脂质过氧化抑制能力,并对其进行了相关性分析。结果表明,模拟胃消化过程中,云南金花茶总黄酮、总多酚含量均比口腔消化高,最高分别达229.99、327.65 μg/mL,经肠消化后,总黄酮含量在38.56~78.88 μg/mL之间,总多酚含量在30.04~65.52 μg/mL之间,含量较低。在功能活性测定中,较口腔消化,胃消化阶段的DPPH•、ABTS+•清除能力和铁离子还原能力显著升高,脂质过氧化抑制能力随消化的进行呈上下波动;经肠消化后,DPPH•、ABTS+•清除能力和铁离子还原能力急剧下降,且均比胃消化阶段低,而脂质过氧化抑制能力则趋于平稳或逐渐上升。通过相关性及主成分分析,各指标之间存在一定的关联性。综上所述,云南金花茶是较好的活性物质来源,该研究可为探索云南金花茶在人体消化过程中活性物质的变化及作用机制提供一定的实验基础和新思路。     

Determination of Cu2+ using poly(2-aminothiazole)/ multi-walled carbon nanotubes composite film modified glassy carbon electrodes

2-Aminothiazole was electropolymerized by cyclic voltammetry (CV) on the multi-walled carbon nanotubes (MWCNTs) modified glassy carbon electrode (GCE) surface. Poly(2-aminothiazole)/MWCNTs/GCE was used for determination of copper ions. The anodic peak currents of copper ions evaluated by differential pulse stripping voltammetry (DPSV) are linear with the concentrations in the range from 1.0 x 10(-7) M to 2.0 x 10(-5) M with a linear coefficiency of 0.9985. The detection limit is 2.0 x 10(-9) M calculated for a signal-to-noise ratio of 3 (S/N = 3). The proposed method was applied successfully to the determination of copper ions in drinking water, and the recovery was 96%.     

静电层层自组装法制备纳米ZrO2/活性炭复合材料及其吸附性能研究

采用静电层层自组装技术和溶胶-凝胶法将不同层数、不同含量的纳米二氧化锆(ZrO2)粒子组装于活性炭表面,得到一种新型的复合材料。用比表面测定(N2-BET)、X射线荧光光谱(EDXRF)等对其进行了表征。系统地研究了纳米ZrO2改性的活性炭对水中2,4-二硝基酚的吸附性能。结果表明,改性后活性炭对2,4-二硝基酚的吸附符合Freundlich模型,吸附过程主要受分配作用控制,吸附容量比改性前提高了25%,而接触时间和初始浓度对吸附效果具有显著影响,并且酸性条件有利于吸附的进行。     

基于灰色理论的汽车室内空气品质评价研究

将灰色系统理论引入到汽车内流场品质的研究中,尝试对汽车室内空气品质进行灰色评价。以挥发性有机气体为研究对象,运用灰色关联分析方法把汽车室内的各种VOC浓度与室内空气质量标准联系起来,同时分析了各种挥发性有机气体对TVOC的影响程度,为新车的使用以及汽车室内挥发性有机物的控制提供了建议。通过研究发现,该方法是一种行之有效的汽车室内空气品质评价方法,其原理简单,算法简捷,评价结果客观可靠,有很强的实用性。     

两亲性嵌段共聚物PS-b-P4VP·BuBr的合成及自组装

采用可逆加成断裂链转移聚合(RAFT)制备了苯乙烯和4-乙烯基吡啶嵌段共聚物(PS-b-P4VP),并用溴代正丁烷对其进行季铵化,得到两亲性嵌段共聚物PS-b-P4VP.BuBr。采用核磁共振(1H-NMR)、红外光谱(FT-IR)、凝胶渗透色谱(GPC)和有机元素分析对聚合物结构进行表征分析。将PS-b-P4VP.BuBr在水溶液中进行自组装研究,透射电镜(TEM)结果显示,共溶剂N,N-二甲基甲酰胺(DMF)和四氢呋喃(THF)的比例可以调控聚集体的形态,随着THF含量增加,聚集体形态从球形依次向棒状、大复合胶束转变。     

一种5-羟基吲哚制备新工艺

介绍了一种以吲哚为原料合成5-羟基吲哚的新方法。该方法采用磺酸基保护吲哚活泼3位,取代吲哚5位获得了5-溴吲哚,经水解合成目标物。本方法首次采用相转移催化剂实现了5-溴吲哚得高效率水解。优化了合成工艺：反应物乙酸酐与2-磺酸钠-二氢吲哚一水合物的摩尔配比为20∶1,pH为11,选用四甲基氯化铵相转移催化剂,产物得率达到了81.2%。