Additional Isoquinoline Alkaloids from Lltsea Cubeba

By combination of centrifugal partition chromatography (CPC) and common separation methods, seven additional known bases were isolated and characterized from the reinvestigation of L. cubeba besides three previously isolated bases- isocorydine (10), N-methyllaurotetanine (9), and boldine (2). They are laurolitsine (1), laurotetanine (3), isoboldine (4), norisocorydine (5), N-methyllindcarpine (7), isodomesticine (8), and glaziovine (6). Among these, compound 9 is the most abundant (7.5 × 10^?4) and will be modified for pharmacological tests. This work will be of value for chemotaxonomy.     

Influence of physical properties and operating parameters on hydrodynamics in Centrifugal Partition Chromatography

Besides the selection of a suitable biphasic solvent system the separation efficiency in Centrifugal Partition Chromatography (CPC) is mainly influenced by the hydrodynamics in the chambers. The flow pattern, the stationary phase retention and the interfacial area for mass transfer strongly depend on physical properties of the solvent system and operating parameters. In order to measure these parameters we visualized the hydrodynamics in a FCPC-chamber for five different solvent systems with an optical measurement system and calculated the stationary phase retention, interfacial area and the distribution of mobile phase thickness in the chamber. Although inclined chambers were used we found that the Coriolis force always deflected the mobile phase towards the chamber wall reducing the interfacial area. This effect increased for systems with low density difference. We also have shown that the stability of phase systems (stationary phase retention) and its tendency to disperse increased for smaller values of the ratio of interfacial tension and density difference. But also the viscosity ratio and the flow pattern itself had a significant effect on retention and dispersion of the mobile phase. As a result operating parameters should be chosen carefully with respect to physical properties for a CPC system. In order to reduce the effect of the Coriolis force CPC devices with greater rotor radius are desirable.     

Mn-CCA-CPC浊点萃取火焰原子吸收法测定水环境中锰

使用浊点萃取的方法分离富集水环境中痕量的锰离子,创新性地使用钙羧酸(CCA)与阳离子表面活性剂氯代十六烷基吡啶(CPC)为络合剂与锰离子形成更稳定的三元络合物,以TritonX-114为萃取剂浊点萃取分离富集水环境中的痕量锰,同时采用火焰原子吸收法进行测定,建立了测定水环境中痕量锰的新方法。对影响浊点萃取的主要因素如pH、TritonX-114的用量、CCA用量、CPC用量、NaCl用量、共存离子影响、加热温度、加热时间、离心时间、冰浴时间进行了优化。在优化的实验条件下,Mn2+-CCA-CPC体系分离富集锰有很好地效果,能够很好的克服基体干扰,浊点萃取体系在锰含量0.3～1.5 mg·L-1时呈现良好的线性关系。方法的灵敏度为1.939 mg·L-1,精密度为0.39%,检出限为(3σ)0.27 μg·L-1。测定自来水与井水中的锰含量的结果为33.5和64.5 μg·L-1,同时做加标回收实验,回收率在99.1%～101.5%之间。符合国际标准,因此该方法能够成功应用到水环境中的锰含量的测定,结果令人满意。     

组合式发光二极管路灯反射器的设计

设计了一组合式路灯反射器,以使发光二极管（LED）路灯在道路照明时产生矩形光斑和均匀照度。在非成像光学基础上,利用复合抛物面的高性能集光作用和机械设计软件的强大作图功能,设计了一款分段组合复合抛物面反射器（CPC）。基于“边缘光线原理”和”裁剪法”,此款反射器能将朗伯型发光的LED光束整形为近似矩形分布,出光效率达96％以上。理论模拟证明：在高度为10m,范围为10m×30m内利用此反射器进行二次配光的LED路灯的照度均匀度达0．5以上。该反射式LED路灯光束整形器结构简单,光学效率高、成本低廉,模拟结果完全达到了目前我国国家道路照明规范要求。     

含铕配合物荧光纳米纤维的制备及光学性质的研究

通过静电纺丝技术,将发光良好的稀土配合物Eu(DBM)₃·H₂O和Eu(DBM)₄·CPC纳米微粒复合到水溶性的聚乙烯基吡咯烷酮中,制备了具有稀土铕离子红色特性荧光的聚合物纳米纤维。通过对稀土配合物以及聚合物纳米纤维样品扫描电镜和透射电镜的测试,发现当稀土配合物复合到聚合物纳米纤维中后,由于与聚乙烯基吡咯烷酮乙醇溶解性良好,其微观结构发生了变化,得到了50～100 nm左右的比较均匀的线状结构。同时,通过对稀土配合物以及聚合物纳米纤维样品的荧光激发、发射光谱及荧光寿命进行研究,表明稀土配合物在聚合物纳米纤维中比其在粉末状有更高的发光强度及更长的荧光寿命,其原因在于高分子纳米纤维为稀土配合物提供了较稳定的化学环境。     

Chemical Constltuents from the Roots of Zizyphus jujuba Mill. var. spinosa (I)

The chemical constituents of the roots of Zizyphus jujuba Mill. var. spinosa were investigated with a combination of Sephadex LH-20 column, centrifugal partition chromatography and RP-18 low pressure liquid chromatography. We isolated seven flavonoids-quercetin ( 1 ), (+)-dihydroquercetin ( 2 ), (+)-dihydrokaempferol ( 7 ), quercetin-3-0-β-glucoside ( 8 ), 2-hydroxynaringenin ( 11 ), rutin ( 12 ), and quercetin 3-0-(2^G-β-D-xylopyranosylrutinoside) ( 13 ); four catechins-(-)-gallocatechin ( 3 ), (-)-epigallocatechin ( 4 ), (-)-catechin ( 5 ), and (-)-epicatechin ( 6 ); and two phenolic carboxylic acids-p-hydroxybenzoic acid ( 9 ) and protocatechuic acid ( 10 ) from the water soluble fraction of the ethanolic extract NMR date of 13 were assigned by 2D NMR techniques.     

Spectrophotometric determination of magnesium in pharmaceutical preparations by cost-effective sequential injection analysis

A simple and rapid, inexpensive spectrophotometric method was proposed for magnesium assay in pharmaceutical preparations by sequential injection analysis (SIA). The method is based on the reaction between o-cresolphthalein complexone (CPC) and Mg(II) in alkaline media, yielding a pink colored complex with absorption maximum at 570 nm. Since the formation constant between Ca-CPC and Mg-CPC is similar, initially a sample/standard solution was aspirated into the holding coil followed by a mixture of masking-buffer solutions. This was done because masking of calcium should be accomplished before Mg-CPC complexation. Then the reagent was introduced into the reaction coil to produce a colored complex, which is measured spectrophotometrically at 570 nm. In this way the interference of calcium was reduced. Furthermore, all the parameters that affect the reaction were evaluated. The calibration curve is linear over a range of 0-20 mg l⁻¹ of Mg(II) with a detection limit of 0.24 mg l⁻¹. A sample throughput of 80 samples per hour and relative standard deviation <2.0% were achieved. The proposed method was successfully applied for the assay of magnesium in three different compositions of pharmaceutical preparations (tablets). The results were found to be in good agreement with the manual flame atomic absorption spectrophotometry (FAAS) and UV-Vis spectrophotometry methods and with the claimed values by the manufactures. The t-test shows no significant difference at 95% confidence level.     

双硫腙—CPC与铜显色反应的研究和应用

双硫腙——ＣＰＣ与铜显色反应的研究和应用余协瑜罗姿容吴德岚（重庆钢铁高等专科学校应用化学系重庆６３００５０）关键词分光光度法铜双硫腙氯化十六烷基吡啶中图分类号Ｏ６５７．３２双硫腙应用于铜的测定早有报导［１］，但需用ＣＣｌ４萃取。本文研究了ＣＰＣ对铜（...