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1.
痕量尼莫地平测定的紫外薄层色谱扫描法   总被引:1,自引:0,他引:1  
以V氯仿∶V甲醇∶V二氯甲烷∶V正己烷=2.6∶1.2∶1∶5为展开剂,建立了薄层色谱扫描法测定痕量药物尼莫地平的新方法。其Rf值为0.48。扫描波长为365nm,该法的最低检出限为0.005μg,相对标准偏差为2.94%,工作曲线的线性范围为0.005~1μg。用该法测定了加有尼莫地平的血清和尿样,尼莫地平的平均回收率为96.7%~103%。  相似文献   

2.
同时测定体液中咖啡因和茶碱的薄层色谱扫描法   总被引:6,自引:0,他引:6  
研究了同时测定血清、尿样中的咖啡因和茶碱的薄层色谱定量法。在GF254硅胶板上,用乙酸乙酯-氨水(V乙酸乙酯∶V氨水=96∶4)的二元展开体系能将这两种生物碱有效地分离。其Rf值为咖啡因0.46,茶碱0.16。分离后的试样用薄层色谱扫描仪进行扫描定量,测定波长272nm,线性范围咖啡因0.0097~1.94μg,茶碱0.0090~1.80μg。血清及尿样的加标回收率在95.8%~106.5%之间,相对标准偏差2.95%~3.50%。本法较为简便、快速、准确  相似文献   

3.
讨论了用CAS-CPB胶束增溶比色法测定头发中铝含量的最佳实验条件。最大吸收波长为630nm,铝的线性范围为0~4.0μg,变异系数CV=3.2%(n=6),回收率为98%。  相似文献   

4.
讨论了用CAS-CPB胶束增溶比色法测定头发中铝含量的最佳实验条件,最大吸收波长为630nm,铝的线性范围为0 ̄4.0μg,变异系数CV=3.2%(n=6),回收率为98%。  相似文献   

5.
薄层色谱法检测甘薯呋喃萜类毒素   总被引:1,自引:0,他引:1  
沈业寿 《色谱》1997,15(4):328-330
 甘薯呋喃萜类毒素是甘薯受到损害后产生的强制性代谢产物,可用乙醚提取。乙醚提取物分别用5%Na2CO3和蒸馏水洗涤,无水硫酸钠干燥,蒸去乙醚。残渣(粗品)采用薄层色谱法进行检测,以纯品甘薯酮和甘薯酮醇作标样。结果表明:在20℃条件下,在石油醚-醋酸乙酯(21,V/V)和苯-甲醇(91,V/V)两种溶剂系统中,对甘薯酮(C)、甘薯酮醇(A)、化合物B和D的呋喃萜类毒素具有较好的分离效果,Rf值的重复性也较好。展开后的薄层板可以通过CS-930TLC扫描仪在527nm下扫描定量。  相似文献   

6.
本文采用双波长薄层扫描仪,以紫外吸收方式,测定了感冒通片中扑尔敏的含量,其测定波长λs=260nm,参比波长λR=320nm,所用薄层板为GF254,薄层厚度为0.4mm,展开剂为苯∶氯仿∶冰HAC∶甲醇=5∶5∶0.5∶0.6,回收率为101.6%。  相似文献   

7.
对土壤及玉米植株中均三氮苯类除草剂的残留分析   总被引:4,自引:0,他引:4  
刘峰  慕卫  王金信  于金凤 《色谱》1998,16(6):543-544
 土壤或玉米植株样品用V(甲醇)∶V(乙腈)=1∶1提取,提取液用石油醚净化后,浓缩液过C18小柱净化,最后用Nova-PakC18柱进行HPLC分析。回收率:氰草津为82.4%~99.8%,莠去津为85.6%~102.3%,西草净为89.1%~108.4%。  相似文献   

8.
苦荞叶片中芸香甙的薄层色谱定量研究   总被引:1,自引:0,他引:1  
根据芸香甙的理化性质,建立了一种测定植物样品中芸香甙含量的薄层紫外扫描法,采用硅胶GF254薄层板,样品经甲醇提取浓缩后点样,展开剂为乙酸乙酯-甲酸-水(8+1+1)。用薄层色谱扫描仪在波长355nm处测定芸香甙的吸收强度并直接定量。该法操作简便,灵敏度高,定量准确,结果稳定,应用于苦荞叶片中芸香甙含量测定,得到良好结果,线性范围为0~2.0μg/μL,斑点的最低检出限为5.0ng,回收率102%  相似文献   

9.
噻利洛尔的吸附伏安行为   总被引:1,自引:0,他引:1  
曾泳淮  李永明  陈小乐 《分析化学》1999,27(10):1136-1140
在NH3-NH4Cl底液中,噻利洛尔在汞电极上有一线性扫描还原峰,电位Epc=-1.31V(vs,Ag/AgCl),该峰具有明显的吸附性。当CEL浓度较小时,扫描较快,搅拌富集时间较长时,电极反应完全为吸附态的CEL的还原所控制,吸附粒子为CEL中性分子,测得CEL在汞电极上的饱和肿附量为1.03×10^-10mol/L,每个CEL分子所占电极面积为1.57nm^3,CEL在悬汞电极上的吸附符合L  相似文献   

10.
泡沫塑料吸附—溶出计时电位法测定地质物料中痕量铊   总被引:7,自引:0,他引:7  
张勤  周丽沂 《分析化学》1995,23(7):817-820
本文提出了泡沫塑料吸附解脱新体系,建立了泡沫塑料吸附-溶出计时电位法测定地质物料中痕量铊的新方法。方法检出限0.03μg/g;铊的含量水平分别为0.71μg/g和1.6μg/g时的测定精密度为3.45%和3.28%;工作曲线线性范围为5 ̄1500ng/mL;回收率为97.5% ̄98.0%。  相似文献   

11.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

12.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

13.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

14.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

15.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

16.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

17.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

18.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

19.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

20.
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