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复方维生素B片中主要成分的高效毛细管电泳电化学法检测 总被引:8,自引:1,他引:7
采用高效毛细管电泳-电化学检测法同时测定复方维生素B片中的主要成分维生素B1,B12,B6和C的含量;研究了电极电位,运行缓冲溶液的浓度和酸度,电泳电压和进样时间等对电泳的影响,以微铂电极为工作电极,检测电位+0.5V(vs SCE),在pH9.0的15mmol/L Tris-1mmol/L H3BO3缓冲溶液中,上述4组分在5min内获得基线分离;维生素B1,B12,B6和C的线性范围分别为2.1mg/L-1.0g/L,6.0mg/L-0.80g/L,1.4mg/L-0.72g/L和0.97mg/L-0.44g/L检出限分别为0.50mg/L,1.0mg/L,,0.65mg/L和0.40mg/L;5次测定峰高的相对标准偏差分别为2.4%,3.0%,3.1%,和2.5%,5次测定的平均回收率分别为99%,102%,98%和100%。 相似文献
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阻抑速差催化光度法测定痕量色氨酸和酪氨酸 总被引:8,自引:1,他引:7
研究了色氨酸、酪氨酸在硫酸环境中抑制碘对亚砷酸与硫酸铈氧化还原反应的催化作用及动力学条件。在0.001mol/L Ce(SO4)2,0.00125mol/L As2O3,0.013mg/L KI,0.025g/L和0.25g/L NaCl溶液中测定色氨酸和酪氨酸,其线性范围分别为0.0~0.65mg/L,0.0~4.0mg/L和0.0~1.3mg/L。0.10~4.0mg/L,用联立方程分别求出各自含量。用此法对醇溶蛋白质和混合氨基酸溶液中色氨酸和酪氨酸进行测定,混合氨基酸的色氨酸、酪氨酸测量值为0.8037g/L,3.591g/L;蛋白质的色氨酸、酪氨酸测量值为1.8g/kg、3.43g/kg;回收率在88%~109%;色氨酸和酪氨酸的RSD分别为4.8%和5.2%,结果满意。 相似文献
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五氧化二钒中微量镁的测定 总被引:1,自引:0,他引:1
本文采用共沉淀定量分离方法对五氧化二钒中所含微量镁进行极谱测定。检出限为1.5mg/L,线性范围为0~0.4mg/L。精确度为:标准偏差S=0.14,变异系数CV=1.92%;相对误差为2.3%. 相似文献
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高效毛细管电泳电导法快速检测复方维生素B片中的VBl、VBl2、VB6和VC 总被引:1,自引:0,他引:1
采用高效毛细管电泳电导法同时分离、测定了复方维生素B片中的主要成分VB1,VB12,VB6和VC的含量。研究了运行缓冲溶液的酸度和浓度、电泳电压、进样时间等因素对电泳的影响。在优化的实验条件下:40mmol/L Tris-4mmol/L H3BO3(pH8.0)的缓冲溶液中加入0.30mmol/L CTAB(溴化十六烷基三甲基铵),分离电压为15kV,上述4组分在5min内得到良好的分离。维生素B1,B12,B6和VC的线性范围分别为5.5~1.0mg/mL;15~1.5mg/mL;1.0~0.40mg/mL和6.6~0.80mg/mL;检测限分别为0.80μg/mL,4.0μg/mL,0.50μg/mL,2.9μg/mL;5次测定峰高的相对标准偏差分别为2.2%,1.6%,3.9%,2.8%。5次测定的平均回收率分别为99%,94%,l00%,97%。 相似文献
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环丙沙星荷移反应及荧光光谱性质研究 总被引:6,自引:0,他引:6
研究了环丙沙星(CPFX)与电子受体2,3-二氰-5,6-二氯-1,4对苯酯(DDQ)之间的荷移反应。实验结果表明:DDQ与CPFX的荷移反应需在丙酮-甲醇(1:4)介质中进行。两者于40℃水浴中恒温30min即可形成1:1络合物,其荧光发射较CPFX有显著的增强。在0.107.2mg/L浓度范围内,荧光强度与质量浓度呈良好线性关系;其检出限为0.1mg/L。本方法用于片剂中环丙沙星的含量测定,其回收率为96.6%-100.2%;标准偏差为1.3%-2.6%。 相似文献
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火焰原子吸收光谱法直接测定食用菌中的铅和镉 总被引:2,自引:0,他引:2
采用火焰原子吸收法直接测定了食用菌中铅和镉的含量。方法灵敏、准确,测定时无须富集、萃取,操作简便,快速,铅和镉的相对标准偏差分别在3.3%~7.3%和3.1%~7.5%之间。回收率在94%~106%和95%~105%之间;检出限为0.016mg/L和0.008mg/L。 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
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
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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
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
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
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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
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
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
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
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
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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
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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
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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