茶叶中茶多酚的提取、测定及应用

茶多酚是茶叶中多酚类物质的总称,在食品、油脂、保健、医药、日化、精细化工等领域都有广泛的应用。茶多酚的提取和应用研究成为国内外开发“绿色工程”的热门课题之一。本文研究的内容是茶叶中茶多酚的提取与测定,主要目的是测定茶叶在不同条件下荼多酚的含量,然后相互比较。例如：茶汤放置时间,泡茶次数及pH对茶多酚含量的影响。随着人们保健意识的增强,都希望自己每日饮用的茶水中的茶多酚的含量多一些,因此我们研究了不同条件下从茶水中获得茶多酚的最佳条件。     

被窃的文件

夜喇人静。在F博士研究所的附近潜伏着一个小偷。 至今为止,F博士已相继发明了一系列性能优异的药物,据最近传出的消息说,他即将又要完成一种新型药物的研制。     

缓释调控优化教育

偶感风寒．服药时无意瞥见“缓释片”这么个词儿．不禁思忖：这价格略高的“缓释片”较之“普通片”究竟优越性何在呢？原来“缓释片”之所以逐步取代“普通片”的地位是因为：1．可以减少服药次数,特别适用于需要长期服药的慢性病病人：2．它能提供持久平稳的有效血药浓度．有利于提高药物使用的安全性．减少药物的不良反应：3可减少药物的总剂量．控制最小剂量．达到最大药效。     

Determination of 5-Fluorouracil in Human Plasma by High- Performance Liquid Chromatography （HPLC

5-Fluorouracil (5-FU) has a broad spectrum of anti-tumor activity, widely applied to the treatment of cancers. However, it is necessary to determine the plasma concentration of 5-FU in clinical practice due to its narrow therapeutic index. Therefore, a simple, economic and sensitive high-performance liquid chromatography (HPLC) method was developed and validated for the determination of 5-FU in human plasma. Ethyl acetate was chosen as extraction reagent. Chromatographic separation was performed on a Diamonsil C18 column (250 mm × 4.6 mm i.d., 5 μm) with the mobile phase consisting of methanol and 20 mmol/L ammonium formate using a linear gradient elution at a flow rate of 0.8 mL/min. 5-FU and 5-bromouracil (5-BU) were detected by UV detector at 265 nm. The calibration curve was linear over the concentration range of 5—500 ng/mL and the correlation coefficient was not less than 0.992 6 for all calibration curves. The intra- and inter-day precisions were less than 10.5% and 4.3%, respectively, and the accuracy was within ±3.7%. The recovery at all concentration levels was 80.1±8.6%. 5-FU was stable under possible conditions of storing and handling. This method is proved applicable to therapeutic drug monitoring and pharmacokinetic studies of 5-FU in human.     

谈谈熔点测定

在有机化学这门学科中,熔点测定是最为常见和实用的一门基本操作技能。掌握好这门技术无论对学习还是工作都是非常重要的。     

Determination of the volatile fraction of coal tar

The coal tar was qualitative and quantitative anMyzed by gas chromatography （GC） method. 74 components were identified exactly by gas chromatographY-mass spectrometry （GC-MS）. 31 components （37%） were quantitatively analyzed by gas chromatography-flame ionization detector （GC-FID）. The linearity, accuracy, precision, limit of detection （LOD） and limit of quantitative （LOQ） determination were inspected. The scope of quantitative analysis by CC was discussed. The experimental results of thermogravimetric analysis （TGA） proved that GC quantitative analysis of the coal tar was reliable.     

医药行业:将迎来新一轮高增长

主要观点:一、基本药物制度2月底前在30%基层医疗机构建立国务院医改领导小组办公室1月21日在安徽合肥召开实施国家基本药物制度现场经验交流会上表明,国家基本药物制度涉及亿万群众的切身利益,事关医改全局。     

莱赛尔纤维混纺比的分光光度法测定

莱赛尔纤维G和莱赛尔纤维A的性质非常接近,对其定性定量鉴定十分困难。建立了一种分光光度测定方法,对莱赛尔纤维G和莱赛尔纤维A进行了定性鉴别,并对莱赛尔纤维混纺产品进行了定量测定。用质量分数为60%硫酸作为溶解介质,测定莱赛尔纤维溶液的紫外-可见吸收光谱,利用紫外-可见吸收光谱对莱赛尔纤维G和莱赛尔纤维A进行定性鉴别。测定莱赛尔纤维及其混合物的吸光度值,根据Lasbeli定理计算了其混纺比。分析结果与实际配比的偏差范围为-3.20%～3.17%,误差全部在FZ/T 01053-2007的允差范围内,说明采用该方法来进行定量测定是可行的。     

天然药物化学教学如何培养学生的创新能力

本文探讨了天然药物化学教学中培养学生创新能力的必要性,提出在理论教学、改革教学方法、建立新的评价体系等方面培养学生的创新能力。