Detection of catecholamine metabolites in urine based on ultra-high-performance liquid chromatography–tandem mass spectrometry

The excretion of neurotransmitter metabolites in normal individuals is of great significance for health monitoring. A rapid quantitative method was developed with ultra-performance liquid chromatography–tandem mass spectrometry. The method was further applied to determine catecholamine metabolites vanilymandelic acid (VMA), methoxy hydroxyphenyl glycol (MHPG), dihydroxy-phenyl acetic acid (DOPAC), and homovanillic acid (HVA) in the urine. The urine was collected from six healthy volunteers (20–22 years old) for 10 consecutive days. It was precolumn derivatized with dansyl chloride. Subsequently, the sample was analyzed using triple quadrupole mass spectrometry with an electrospray ion in positive and multireaction monitoring modes. The method was sensitive and repeatable with the recoveries 92.7–104.30%, limits of detection (LODs) 0.01–0.05 μg/mL, and coefficients no less than 0.9938. The excretion content of four target compounds in random urine samples was 0.20 ± 0.086 μg/mL (MHPG), 1.27 ± 1.24 μg/mL (VMA), 3.29 ± 1.36 μg/mL (HVA), and 1.13 ± 1.07 μg/mL (DOPAC). In the urine, the content of VMA, the metabolite of norepinephrine and adrenaline, was more than MHPG, and the content of HVA, the metabolite of dopamine, was more than DOPAC. This paper detected the levels of catecholamine metabolites and summarized the characteristics of excretion using random urine samples, which could provide valuable information for clinical practice.     

高校化学教学实验室小型试剂库改造

目前高校化学教学实验室小型试剂库(暂存库)存在较多安全隐患,但一般体量较小,容易被相关管理者忽视,可能会造成实验室安全事故的发生。本文结合国家级实验教学示范中心(中国科学技术大学)化学实验教学实验室的实际情况,阐述了化学教学实验室小型试剂库改造的实践经验,为其他高校实验室试剂库的改造提供符合法律法规和国家标准要求的、适应面广、操作性强的可借鉴经验。     

融入统筹理念的分析化学实验教学

基于一流创新人才培养的要求和分析化学实验课程的特点,介绍了如何在分析化学实验教学中融入统筹学理念,旨在培养学生的统筹能力,拓展化学实验课程的育人功能,实现知识技能传授和综合能力培养并重的教学目的,将创新人才培养的教学理念落到实处。     

外电场作用下离子液体振动光谱变化的分子动力学模拟研究

Vibrational spectroscopy is a powerful tool for studying the microstructure of liquids, and anatomizing the nature of the vibrational spectrum (VS) is promising for investigating changes in the properties of liquid structures under external conditions. In this study, molecular dynamics (MD) simulations have been performed to explore changes in the VS of 1-ethyl-3-methylimidazolium hexafluorophosphate ([Emim][PF₆]) ionic liquid (IL) under an external electric field (EEF) ranging from 0 to 10 V·nm^-1 at 350 K. First, the vibrational spectra for [Emim][PF₆] IL as well as its cation and anion are separately obtained, and the peaks are strictly assigned. The results demonstrate that the VS calculated by MD simulation can well reproduce the main characteristic peaks in the experimentally measured spectrum. Then, the vibrational spectra of the IL under various EEFs from 0 to 10 V·nm^-1 are investigated, and the intrinsic origin of the changes in the vibrational bands (VBs) at 50, 183, 3196, and 3396 cm^-1 is analyzed. Our simulation results indicate that the intensities of the VBs at 50 and 183 cm^-1 are enhanced. In addition, the VB at 50 cm^-1 is redshifted by about 16 cm^-1 as the EEF is varied from 0 to 2 V·nm^-1, and the redshift wavenumber increases to 33 cm^-1 as the EEF is increased to 3 V·nm^-1 and beyond. However, the intensities of the VBs at 3196 and 3396 cm^-1 show an obvious decrease. Meanwhile, the VB at 3396 cm^-1 is redshifted by about 16 cm^-1 when the EEF increases to 3 V·nm^-1, and the redshift increases to 33 cm^-1 with an increase in the EEF beyond 4 V·nm^-1. The intensity of the VB at 50 cm^-1 increases because of the increase in the total dipole moment of each anion and cation (from 4.34 to 5.46 D), and the redshift is attributed to the decrease in the average interaction energy per ion pair (from -378.7 to -298.0 kJ·mol^-1) with increasing EEF. The intensity of the VB at 183 cm^-1 increases on account of the more consistent orientations for cations in the system with increasing EEF. The VB at 3196 cm^-1 weakens visibly because a greater number of hydrogen atoms appear around the carbon atoms on the methyl/ethyl side chains and the vibrations of the corresponding carbon-hydrogen bonds are suppressed under the action of the EEF. Furthermore, the intensity of the VB at 3396 cm^-1 decreases due to the decrease in the intermolecular ⁺C-H···F^- hydrogen bonds (HBs), while the relaxation effect that is beneficial for the formation of HBs simultaneously exists in the system under the varying EEF, thus causing a redshift of the VB at 3396 cm^-1.     

偶合反应伏安酶联免疫分析测定人血清乙型肝炎E抗原

本文提出了一种偶合反应伏安酶联免疫分析测定人血清乙型肝炎Ｅ抗原（ＨＢｅＡｇ）的新方法。本法对酶标乙型肝炎Ｅ抗体测定的灵敏度比经典的ＥＬＩＳＡ显色光度法高２０倍。对ＨＢｅＡｇ的测定采用双抗体夹心法，对ＨＢｅＡｇ阳性对照血清的测定范围为１：１～１：１０２４，灵敏度比ＥＬＩＳＡ显色光度法高１６倍。用所建立的方法对实际病人血清样品进行了测定，并与现行的ＥＬＩＳＡ显色光度法进行对照，两种方法相关性很好。     

meso－5，10，15，20－四（3，4，5－三甲氧基苯基）卟啉的晶体和分子结构

用Ｘ－射线测定了ｍｅｓｏ－５，１０，１５，２０－四（３，４，５－三甲氧基苯基）卟啉的溶剂（正庚烷）合物（ＴＴＯＭＰＰ·２Ｃ＿７Ｈ＿（１６））的晶体结构。实验表明，该化合物（Ｃ＿（７０）Ｈ＿（８６）Ｎ＿４Ｏ＿（１２））的晶体属三斜晶系，空间群Ｐ１，ａ＝８．７４９（６），ｂ＝１５．１２９（６），ｃ＝１６．４４９（３），ａ＝６０．０７（３），β＝７０．６４（４），γ＝８１．７０（５），Ｖ＝１７７９．６，Ｍ＿ｒ＝１１７５．４９，Ｚ＝１，Ｄ＿ｃ＝１．０９７ｇ／ｃｍ￣３，μ＝０．６９７ｃｍ￣（－１），Ｆ（０００）＝６３０。讨论了卟啉环上取代基的电子和立体效应及卟啉与铁（Ⅲ）离子配位后铁（Ⅲ）离于对卟啉结构参数的影响。     

无外加催化剂条件下的克脑文盖尔缩合反应与溶剂效应的研究

本文报道了无外加催化剂条件下以DMF为溶剂芳香醛与丙二腈或氰基乙酸乙酯进行克脑文盖尔缩合反应, 此法产率较高。讨论了影响溶剂效应的一些因素。     

聚氨酯-丙烯酸酯杂化乳液结构与性能的影响

以聚四氢呋喃醚二醇（PTMG）、异氟尔酮二异氰酸酯（IPDI）、亲水单体二羟甲基丙酸（DMPA）,乙二胺为主要原料,制备了稳定的水性聚氨酯乳液.然后以苯乙烯（St）、丙烯酸丁酯（BA）为单体,过硫酸钾为引发剂,在不外加乳化剂的条件下,运用物理共混、化学复合和化学共聚三种方法对该水性聚氨酯乳液进行改性研究.用FTIR技术对聚氨酯-丙烯酸酯杂化乳液的结构进行了对比与表征;通过粘度测定、粒度分析、力学性能和耐水性能测试、DSC分析,研究了不同改性方法对乳液及其胶膜性能的影响.结果表明,化学共聚的改性方法对原水性聚氨酯的耐水性的改良效果最好,能够得到稳定且综合性能较优的聚氨酯-丙烯酸酯杂化乳液.     

Determination of triptolide and triptonide in human plasma by high-performance liquid chromatography

An isocratic high-performance liquid chromatographic method for determination of triptolide and triptonide in human plasma is described. Plasma samples were extracted with OasisHLB solid-phase extraction (SPE) cartridges. After pretreatment, they were separated on a SymmetryShieldRP(18) column with a mobile phase of acetonitrile-water (40:60,v/v) at 40 degrees C. The effluent was monitored at UV 217 nm. Linearity (0.010-1.0 mg/L) was good, and the lower limit of detection was 3 ng/mL for triptolide and 4.5 ng/mL for triptonide (S/N = 3). The relative standard deviations of intra- and inter-day assay were less than 15% and the recoveries were better than 80%. The developed method was applied to the determination of triptolide and triptonide concentration in a patient's plasma after taking the medicament containing Tripterygium wilfordii Hook. F.