冷水花药材的薄层指纹图谱研究

采用硅胶GF254板,分离冷水花80%乙醇提取物中石油醚和乙酸乙酯两个萃取部位的化合物,分别以石油醚-三氯甲烷-丙酮(5∶0.5∶1)、石油醚-三氯甲烷-丙酮(2∶1∶1)为展开系统,对上述两个萃取部位进行薄层色谱研究.实验得到的冷水花药材各萃取部位的薄层指纹图谱斑点清晰,能有效鉴别冷水花药材.     

高效薄层色谱扫描法同时测定滁菊中木犀草素、芹菜素、金合欢素含量

目的:采用高效薄层色谱扫描法(HTLCS)同时测定滁菊中木犀草素、芹菜素和金合欢素的含量。方法:采用硅胶GF254高效薄层板条带点样,以甲苯∶乙酸乙酯∶甲酸∶水=17∶7∶3∶2上层溶液为展开剂,上行展开,于365nm波长下进行直线扫描,测定滁菊中的木犀草素、芹菜素、金合欢素的含量。结果:分别在0.066 1～0.335 2μg(r=0.999 9),0.068 4～0.333 8μg(r=0.997 9)、0.064 0～0.334 2μg(r=0.995 2)范围内,木犀草素、芹菜素、金合欢素线性关系良好;平均回收率分别为99.9%、100.65%、101.3%,RSD分别为1.55%、1.41%、1.64%。结论:以HTLCS为质量控制方法,建立了一种简便、快速、准确的药物检测方法。     

TLC-SERS法快速分析抗精神失常类中药的化药成分

建立了一种薄层色谱(TLC)结合表面增强拉曼光谱(SERS)用于快速检测抗精神失常类中药中非法掺杂化学成分的方法。通过优化银溶胶、动态-表面增强拉曼光谱(D-SERS)检测方法及激光强度等因素后,利用TLC对中药基质和掺伪4种化药成分,即奋乃静、卡马西平、利培酮、舒必利进行初步分离,以三氯甲烷∶甲醇∶水(8∶2∶0.2)为展开剂,于254 nm紫外灯下检视定位,进而使用SERS技术对分离的微量物质进行鉴别。结果表明,该方法具有专属性、灵敏度好等特点,且检测限可低至0.02 mg/m L;与HPLC法相比,该方法简单快速,无需样品前处理,在现场快速检测方面具有广阔的应用前景。     

高效液相色谱-电喷雾质谱法鉴定玫瑰花中低聚原花青素

建立了采用高效液相色谱-电喷雾质谱法(HPLC-ESI-MS)对玫瑰花提取物中的多种低聚原花青素进行分析鉴定的方法.原花青素用体积分数80%甲醇水溶液从玫瑰花中超声提取后,以乙腈-0.1%甲酸水溶液为流动相,在Waters SunFire-C18柱上进行梯度洗脱分离.在负离子模式下采用全扫描(Scan)和选择离子监测模式(SIM)将几种低聚原花青素进行了选择性的分离.结果表明:共检测到玫瑰花提取物中共含有儿茶素、表儿茶素和表儿茶素没食子酸酯3种单体、3种二聚体及3种三聚体等.建立的方法可以较好地解决玫瑰花中各种低聚原花青素的定性检测,了解提取物中原花青素的成分.     

玉米芯降解液糖类成分薄层色谱法分析技术优化

薄层色谱分离效果的好坏,很大程度上取决于展层剂的组成和配比,还会受硅胶板的活化度、环境温度、显色剂和点样量手法等因素的影响.本文报道了采用薄层色谱法分析玉米芯降解液中单糖的成分,着重对多种展层剂进行优化研究.研究结果显示以正丁醇∶乙酸乙酯∶水=7∶2∶1为展层剂分离糖的效果较好,本文还显示以苯胺-二苯胺-磷酸为显色剂的糖显色效果较好.同时,用上述优化的方法对不同酸浓度处理的玉米芯降解液进行分析研究,可以准确、清晰、便利地定性检测出玉米芯木聚糖中单糖的组分.     

RP—HPLC法测定清咽口服液中龙胆苦苷的含量

目的:建立以反相高效液相色谱法(RP-HPLC)测定清咽口服液中龙胆苦苷含量的方法.方法:经测定波长的选择、线性关系考察、精密度实验、稳定性试验、重复性实验和加样回收实验,确定以下色谱条件:色谱柱为kromasil C18(250mm×4.6mm,5μm),流动相为甲醇-水(35∶65),流速为1mL·min-1,检测波长为270nm.测得3批清咽口服液中龙胆苦苷的含量.结果:龙胆苦苷进样量在0.354～4.448μg范围内与峰面积积分值呈良好线性关系(r=0.999 2);平均回收率为99.06%,RSD=2.0%(n=5).结论:所建立RP-HPLC法简便、快速、准确,可用于清咽口服液的质量控制.     

超声波辅助固相萃取高效液相色谱法测定橡胶中的MBT

建立一种快速溶剂萃取—高效液相色谱检测橡胶中的2-巯基苯并噻唑(MBT)含量的方法.采用超声波辅助丙酮溶解橡胶样品,再采用C18固相萃取小柱萃取其中的MBT,并选择合适的高效液相色谱条件分离测定MBT.选用Zorbax eclipse XDB C18液相色谱柱,V甲醇∶V水∶V0.1%甲酸=60∶35∶5为流动相,紫外波长320 nm进行检测.通过考察最佳预处理萃取条件和高效液相色谱条件下MBT含量的色谱图,根据色谱峰面积采用外标法进行定量分析,MBT的浓度在1.0～12.0 ppm范围内呈良好线性,回归方程为A=-15.1+71.2C(C的单位为ppm),相关系数:r=0.99951,标准回收率为95%～106%.该方法可用于橡胶样品中MBT的测定.     

薄层扫描法测定雷公藤口服液中总内脂的含量

目的 :建立雷公藤口服液含量测定方位 方法 :采用醇提 ,氧化铝柱层分离 ,以醋酸∶石油醚 (2∶1 )为展开剂 ,薄层扫描法测定雷公藤总内酯的含量 (λS=52 5nm ,λR=70 0nm) 结果 :线性范围 :1 0～ 5 0 μg,平均回收率 :99 83 % ,RSD为 0 2 6 % 结论 :该方法准确可靠 ,操作简单 ,可适用于该制剂质量控制     

乙丙昔罗中杂质限量检查方法的研究

目的:探讨薄层层析法(TLC)用于乙丙昔罗中杂质限量检查的效果。方法:以硅胶GF254薄层板为吸附剂,石油醚:乙酸乙酯:冰醋酸(1.0∶0.5∶0.04,v/v)为展开剂,检测波长254nm,比较供试品与杂质斑点的大小和颜色。结果:产品所含杂质量小于1%。结论:该方法可用于乙丙昔罗的杂质限量检查,效果良好。     

高效薄层色谱双波长扫描法测定冠心通脉灵片中葛根素的含量

在硅胶G高效薄层色谱板上,采取双波长薄层扫描法测定了冠心通脉灵片中葛根素的含量.本法快速,简便,方法可靠,板简误差小,平均回收率为99.80%变异系数为1.39%.     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.