吡嗪缩氨基脲配体铜/锌配合物的晶体结构及荧光性质

合成并通过单晶X射线衍射、元素分析及红外光谱表征了配合物[Cu₂（L）₂Br₂]·CH₃OH（1）和[Zn₂（L）₂（CH₃COO）₂]·2CH₃OH（2）的结构（HL为3-乙基-2-乙酰吡嗪缩4-苯基氨基脲）。单晶衍射结果表明,配合物1中,中心Cu（Ⅱ）离子与来自1个三齿缩氨基脲配体阴离子和2个μ²-桥联的溴离子配位,拥有扭曲的四方锥配位构型。配合物2中Zn（Ⅱ）离子配位构型与配合物1中Cu（Ⅱ）离子的相同,周围的供体原子为N₂O₃。配合物2中的2个醋酸根的配位模式不尽相同,其中一个为μ-OCO双齿桥联,另外一个为μ-O单齿桥联。甲醇溶液中,配合物1和2的荧光发射峰与配体HL相似。     

二(2-羟基苄基)胺的合成及其钠盐结构

二(水杨醛亚胺)甲基-2-苯酚和硼氢化钾进行加氢还原反应,不能得到预期的桥联三酚,会发生C-N键断裂生成了二(2-羟基苄基)胺。二(2-羟基苄基)胺在氢氧化钠溶液中生成季铵桥联的二酚钠盐,其分子结构经过了X光单晶衍射分析表征。     

固定Ionic liquid/Silica sol/Nafion膜中的联吡啶钌电化学发光行为的研究及应用

制备了Ionic liquid/Silica sol/Nafion-联吡啶钌复合物膜修饰金电极。采用循环伏安(CV)和电致化学发光(ECL)法,考察了联吡啶钌和左氧氟沙星在此修饰电极上的电化学及其发光行为。结果表明,此修饰电极表现出很好的电化学活性和电化学发光响应。基于左氧氟沙星对固定化联吡啶钌在0.1 mol/L磷酸盐缓冲液中的弱电化学发光信号有较强的增敏作用,建立了电化学发光检测盐酸左氧氟沙星的新方法。在最佳实验条件下,左氧氟沙星浓度在1.0×10-7～1.0×10-4mol/L范围内与相对发光强度呈线性关系(r2=0.998 4),检出限(S/N=3)为1.59×10-9mol/L。连续平行测定2.2×10-5mol/L的左氧氟沙星溶液10次,发光强度的相对标准偏差(RSD)为3.6%。对样品进行回收率试验,回收率在95.6%～103.5%之间,RSD(n=5)为3.0%。该方法具有较高的选择性和灵敏度,样品处理简单快速,用于盐酸左氧氟沙星的测定,结果满意。     

化学合成半乳糖基纤维素

本文研究了一种在酸性条件下合成半乳糖基纤维素的化学方法,探讨了反应时间、纤维素与半乳糖的投料比对共聚物中半乳糖摩尔取代度(MS)的影响。在酸性条件下,纤维素与半乳糖共聚时,少量的半乳糖接枝到纤维素上形成水不溶物,即半乳糖基纤维素;而其余的半乳糖与纤维素降解的少量葡聚糖片段共聚形成水溶物。反应时间从50 min延长到120 min,水不溶物的半乳糖MS基本保持0.12不变;而反应时间为150 min时,水不溶物的半乳糖MS降低为0.073;水溶物主要是由半乳糖组成,葡萄糖含量少。增加半乳糖用量,水不溶物的半乳糖MS增加最后保持0.094不变;随着反应物中半乳糖含量的增加,水溶物的半乳糖MS也是先增加,后保持基本保持15不变。     

超高效液相色谱串联质谱法同时快速测定牛奶中不同类型的11种兽药残留

建立了超高效液相色谱串联质谱测定牛奶中四环素类、青霉素类、磺胺类和泰乐菌素等11种兽药残留的检测方法。样品经乙腈超声提取后离心分离,上层清液稀释10倍后过0.2μm滤膜上机测定。在优化条件下,11种兽药在其线性范围内的相关系数均在0.998以上,定量下限(LOQ,S/N=10)为0.3～15μg/kg,在低、中、高3个水平下的加标回收率为81%～117%,相对标准偏差为0.6%～10.2%。方法用于实际牛奶样品中兽药残留量的测定,结果满意。     

准晶体的研究进展

准晶体是一种介于晶体和非晶体之间的固体。按照其准周期维数的分类方法分为一维、二维、三维准晶体,具有力学性能、电学性能和磁性能。利用其优良的性能特点,可将其应用于表面改性材料和结构材料增强相中。对准晶体的基础研究主要在其原子结构测定、形成因素、成分预测、单质组元的寻找和物理性质的有效调控等方面;而应用研究主要包括其薄膜技术和微纳米化的研究等。     

Lipid profiling of human plasma from peritoneal dialysis patients using an improved 2D (NP/RP) LC-QToF MS method

An improved online two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry (2D LC-QToF MS) system was developed for the lipid profiling of human plasma, in which different lipid classes were separated by the first dimensional normal-phase (NP) LC and different lipid molecular species were separated by the second dimensional reversed-phase (RP) LC. This 2D LC-QToF MS system was built based on a ten-port, two-position valve as the interface, the conditions of which had been optimized and discussed in detail. As two loops were used to trap and transfer the first dimensional elute to the second dimension separately, this new interface suppressed the sample band broadening in the first dimensional column, increased the recovery and repeatability of 2D LC interface, and offered the possibility for the realization of not-stop-flow NP/RP 2D LC system. Finally, 190 endogenous lipid species out of 10 lipid classes were determined within a single run from the plasma of peritoneal patients. This method was also applied to identify the difference in lipid profile between plasma from peritoneal dialysis patients with bad volume status and peritoneal dialysis patients with good volume status. The discovery of 30 potential biomarkers would be helpful to the malnutrition, inflammation, and atherosclerosis syndrome investigation.     

Development of monolith-based stir bar sorptive extraction and liquid chromatography tandem mass spectrometry method for sensitive determination of ten sulfonamides in pork and chicken samples

A highly sensitive method was developed for the simultaneous determination of ten sulfonamides in pork and chicken samples by monolith-based stir bar sorptive extraction (SBSE) coupled to high-performance liquid chromatography tandem mass spectrometry. The samples were freeze-dried and extracted by acetonitrile, then enriched and further extracted by SBSE which was based on poly(vinylphthalimide-co-N,N-methylenebisacrylamide) monolith (SBSE-VPMB) as coating. To achieve optimum extraction performance of SBSE for sulfonamides, several parameters, including pH value and ionic strength in the sample matrix and extraction and desorption time, were investigated in detail. Under the optimal conditions, the limits of detection (S/N?=?3) for target sulfonamides were 1.2–6.1 ng/kg in pork and 2.0–14.6 ng/kg in chicken, respectively. Real samples spiked at the concentration of 0.5 and 5.0 μg/kg showed recoveries above 55 % and relative standard deviations below 12 %. At the same time, the extraction performances of target sulfonamides on SBSE-VPMB were compared with other SBSE based on porous monolith and commercial SBSE.

Magnetic separation of heavy metal ions and evaluation based on surface‐enhanced Raman spectroscopy: Copper(II) ions as a case study

A new approach was developed for the magnetic separation of copper(II) ions with easy operation and high efficiency. p‐Mercaptobenzoic acid served as the modified tag of Fe₂O₃@Au nanoparticles both for the chelation ligand and Raman reporter. Through the chelation between the copper(II) ions and carboxyl groups on the gold shell, the Fe₂O₃@Au nanoparticles aggregated to form networks that were enriched and separated from the solution by a magnet. A significant decrease in the concentration of copper(II) ions in the supernatant solution was observed. An extremely sensitive method based on surface‐enhanced Raman spectroscopy was employed to detect free copper(II) ions that remained after the magnetic separation, and thus to evaluate the separation efficiency. The results indicated the intensities of the surface‐enhanced Raman spectroscopy bands from p‐mercaptobenzoic acid were dependent on the concentration of copper(II) ions, and the concentration was decreased by several orders of magnitude after the magnetic separation. The present protocol effectively decreased the total amount of heavy metal ions in the solution. This approach opens a potential application in the magnetic separation and highly sensitive detection of heavy metal ions.