系列甘草次酸衍生物的合成与波谱测定

目的:合成一系列的甘草次酸衍生物,并对其进行波谱测定。方法:对甘草次酸30位羧基进行修饰,合成甘草次酸甲酯和甘草次酸乙酯;对甘草次酸3位羟基进行修饰,合成甘草次酸甲酯-3-O-乙酸酯和甘草次酸乙酯-3-O-乙酸酯;对甘草次酸11位羰基进行修饰,合成脱氧甘草次酸和脱氧甘草次酸甲酯;对合成物进行波谱测定。结果:合成的甘草次酸衍生物经紫外、红外、质谱、核磁共振氢谱与碳谱的鉴定,均为目标化合物。结论:合成的甘草次酸衍生物可为其后续抗炎活性及毒副作用的研究奠定基础。

长药八宝中酚酸类化合物的分离和含量测定

长药八宝（Hylotelephium spectabile（Bor.）H.Ohba）是耐旱的观赏植物,其全草药用。采用硅胶柱层析,首次对长药八宝中的酚酸类的化学成分进行了分离,分离出反式对羟基肉桂酸、顺式对羟基肉桂酸、异香草酸、对羟基苯甲酸和没食子酸5种化合物。采用紫外光谱法对长药八宝中的反式对羟基肉桂酸、对羟基苯甲酸和没食子酸进行了定量研究。酚酸类成分是高效潜在的天然抗氧化剂,该研究成果将为天然产物的开发与利用以及新药的研制提供数据参考。

漆酶/O_2体系获取半醌自由基的研究

本文综述了在静态条件下用漆酶 /O2 体系获取高稳定浓度半醌自由基阴离子的有效办法。依据漆酶的单电子转移特性 ,分别采用强吸电子基团使未偶电子离域以稳定半醌自由基、适当的有机溶剂延缓半醌自由基衰减和

Determination of contents of 10-Hydroxycamptothecin in Camptotheca acuminata by high-performance liquid chromatogram

The determination method of 10-hydroxycamptothecin in Camptotheca acuminata fruits by high-performance liquid chromatogram (HPLC) was studied. The HPLC analysis was performed on a HIQ sil C18(4.6×250 mm) column with mobile phase of acetonitrilewater (3:7, V:V), flow rate 1 mLmin-1 and UV detective wavelength 266 nm. Extracting 10-hydroxycamptothecin by ultrasonic method from fruits of C. acuminata to prepare samples for analysis was systematically discussed. The optimal extraction condition was carried out by 60% alcohol solution at 60℃ for 50 minutes.

Experimental research on benzene detection using ion mobility spectrometer with a laser ionization source

An ion mobility spectrometer equipped with a laser ionization source is used for the sensitive detection of benzene.Mobility spectra of the benzene are presented.We also discussed the mobility spectra at various concentrations and drift voltages.Detection limits are determined to be in the upper ppb_v range.In the end,the advantages and possibilities of this technique are briefly discussed.

Determination of trace multi-elements in coal fly ash by inductively coupled plasma mass spectrometry

The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with HNO3, HClO4 and FIE The optimum conditions for the determination were obtained. The applicability of the proposed method was validated by the analysis of coal fly ash reference material （NIST SRM 1633a）. The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode （maximum mass resolution R=9 000）. The detection limit is from 0.05 to 0.21 μg/g, and the precision is fine with relative standard deviation less than 4.3%.

Reagent optimization for on-line simultaneous polarographic determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of anextremely large excess of Zn^(2+)

Reagents are optimized for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in zinc sulfate solution, which contains an extremely large excess of Zn^(2+). First, the reagents and their doses for the experiment are selected according to the characteristics of the zinc sulfate solution. Then, the reagent doses are optimized by analyzing the influence of reagent dose on the polarographic parameters(i.e. half-wave potential E_(1/2) and limiting diffusion current I_p). Finally, the optimization results are verified by simultaneously determining trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of an extremely large excess of Zn^(2+). The determination results indicate that the optimized reagents exhibit wide linearity, low detection limits, high accuracy and good precision for the simultaneous determination of trace amounts of Cu^(2+), Cd^(2+) and Co^(2+) in the presence of an extremely large excess of Zn^(2+).