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991.
Summary Two modes of capillary electrophoresis (CE), capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography
(MEKC), were investigated for the separation of 12 aromatic sulphonate compounds. In CZE, although the voltage applied, the
buffer concentration and the pH were optimized for effective separation of the compounds studied, under the best conditions
four of the five amino compounds coeluted, as did naphthalene-1-sulphonic acid and naphthalene-2-sulphonic acid. In MEKC,
sodium dodecyl sulphate (SDS) and Brij 35 were chosen as the anionic and nonionic surfactants and the effect of the concentration
of micelles was examined. The effect of adding methanol as the organic modifier was also investigated with each of these micellar
systems. All the analytes, including the isomers, were completely separated by use of MEKC with Brij 35 but when SDS was used
only 11 compounds were separated because two amino compounds coeluted. 相似文献
992.
Summary A capillary zone electrophoresis method has been developed and validated for the analysis of chlortetracycline and related
substances. The influence of the type of buffer, pH and concentration of the buffer were investigated. In all cases 1 mM EDTA
was added to prevent metal ion complexation. Instrumental parameters such as capillary temperature and applied voltage were
optimised. The following methods is proposed: capillary: fused silica, 44 cm (36 cm effective length), 50 μm i.d.; buffer:
120 mM sodium tetraborate including 1mM EDTA at pH 8.5; voltage: 10 kV; temperature: 25°C; detection wavelength: 280 nm. The
robustness of the method has been examined by means of a full-fraction factorial design. The parameters for validation namely
relative standard deviation, linearity, precision, limit of detection and limit of quantitation are also reported. 相似文献
993.
Elinson M. N. Feducovich S. K. Zaimovskaya T. A. Dorofeev A. S. Vereshchagin A. N. Nikishin G. I. 《Russian Chemical Bulletin》2003,52(4):998-1002
Electrolysis of dialkyl ketones in MeOH in the presence of the NaI—NaOH mediator system placed in an undivided cell involves a process analogous to the Favorsky rearrangement of ,-dihalodialkyl ketones giving rise to methyl esters of ,-unsaturated carboxylic acids in 70—75% substance yields and 60—70% current yields. 相似文献
994.
高效毛细管电泳法测定人血及尿样中甲磺酸帕珠沙星 总被引:1,自引:0,他引:1
采用高效毛细管电泳法测定甲磺酸帕珠沙星在人血及尿样中的含量。实验用未涂层弹性石英毛细管柱,规格是39 cm×50μm(i.d.),其有效长度为28.5 cm。pH 6.0的磷酸盐缓冲溶液(75 mmol/L)作为运行缓冲液,氧氟沙星为内标,在10 kV高压下进样12 s,分离电压选择20 kV,在波长为247 nm的条件下,可有效分离甲磺酸帕珠沙星与氧氟沙星。甲磺酸帕珠沙星在10~700μg/L质量浓度范围内线性良好(r=0.999 6),检出限为5.0μg/L。此方法简便、准确、重复性好。 相似文献
995.
九种嘌呤碱的毛细管区带电泳分离 总被引:5,自引:0,他引:5
用毛细管区带电泳法分离和测定咖啡碱,9-N二羟丙基茶碱,可可碱,腺嘌呤,鸟嘌呤、茶碱、黄嘌呤、尿酸和6-巯基嘌呤,在熔硅毛细管(70cm×75μmi.d,有效长度63cm)内,使用0.01mol/L(pH=10)硼砂缓冲溶液,电压为25kV温度为30℃,真空进样1s,于260nm处检测,可在7min内分离上述到9种嘌呤碱,理论塔板数达到3.0×10^5,检测限达fmol级,方法用于人尿分析,结果令 相似文献
996.
高效毛细管区带电泳检测稀土元素 总被引:4,自引:1,他引:4
本文使用背景电解质为含有吸收作用的肌酸酐和作为配合对离子的羟基异丁酸,肜高效毛区带电泳(CZE)间接紫外光度法测定稀土元素。探讨了背景电解质酸度,吸光共存离子和配合对离子浓度对稀土电泳分离的影响;提出用背景电解质预,沉积法克服毛细管壁的强烈吸附干扰。9种稀土元素混合物11min内完成分离检测。应用内标法对稀土钢样中单个稀土含进行了定量分析。 相似文献
997.
Summary A CZE method has been developed for the purity testing of sulfonic acids. By use of an optimized electrolyte system, short
analysis times and high resolution (R
S=2–4) can be achieved for inorganic anions and for alkyl sulfonic acids from methane-1- to decane-1-sulfonic acid. By use
of indirect UV detection by-products of different sulfonic acids can be determined at the 2 m level, equivalent to 0.02%,w/w.
Presented at the 21st ISC held in Stuttgart, Germany, 15th–20th September, 1996 相似文献
998.
The limiting partial molar volumes of solutes and excess molar volumes of their mixtures with nonpolar solvents are calculated on the basis of precise (error ≤ 5·10?6 g·cm?3) densitometric measurements for dilute solutions of oleic, linoleic, and linolenic acids in tetrachloromethane at 298.15 K. It is found that self-association processes of the components of the mixtures play the key role in dissolution effects of fatty acids in CCl4. As the number of C=C double bonds in the acid molecule increases, acid desolvation becomes less pronounced and is accompanied by compression (reduction of volume) of the structural packing of the solvate complex formed due to the strengthening interaction of the acid with tetrachloromethane. 相似文献
999.
毛细管区带电泳电化学检测器 总被引:4,自引:2,他引:4
本文阐述了毛细管区带电泳探针式安培检测器的构造、工作原理、理论及其与电泳系统的联结技术;介绍了该检测器的应用情况。 相似文献
1000.
Gabor波带片是一种理想的单级聚焦光学元件,但制备困难.本文采用聚焦离子束直写技术成功制备出30环、20扇区的二值化Beynon-Gabor波带片,其有效面积半径为700μm,第一环半径90μm.利用各向异性腐蚀液对硅基底进行开孔,实现了Beynon-Gabor波带片二值化、自支撑、镂空的结构特征.在波长为355 nm的激光下测试其光学性能,结果表明所制备的Beynon-Gabor波带片主光轴上只存在1级衍射叠加后的焦点,不存在高级衍射焦点,具有优异的单级聚焦性能. 相似文献