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碳纳米管修饰电极用于-高效液相色谱对全血中巯基化合物的测定 总被引:11,自引:0,他引:11
研究了羧基化多壁碳纳米管修饰电极 (MWNT CME)的制备方法和该修饰电极对巯基化合物的电催化行为 ,并首次以该修饰电极为电化学检测器 ,与高效液相色谱 (HPLC)联用 ,分离检测了半胱氨酸 (L Cys)和谷胱甘肽 (GSH)两种巯基化合物。结果表明在 3 .0× 1 0 - 7~ 1 .0× 1 0 - 3mol L浓度范围内 ,L Cys和GSH的浓度分别与其氧化峰的峰电流呈良好的线性关系 ,线性相关系数分别为 0 .9987和 0 .9990 ;检出限分别为 1 .2×1 0 - 7mol L和 2 .2× 1 0 - 7mol L。将该方法用于人全血中L Cys和GSH的测定 ,获得了满意的结果 ,为电分析化学在临床医学、生理学等生命科学中的应用提供了新的手段 相似文献
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用毛细管区带电泳 -电化学检测法测定了黄芩及其制剂中黄芩素和黄芩甙的含量。研究了电极电位、电解液酸度和浓度、电泳电压及进样时间等对电泳的影响 ,得到了较为优化的测定条件。以直径为300μm的碳圆盘电极为检测电极 ,电极电位为0.90V(vsSCE) ,在100mmol/L硼酸盐缓冲液(pH9.0)中 ,上述两组分在8min内完全分离。黄芩素和黄芩甙浓度与电泳峰电流分别在5.0×10 -7~1.0×10 -3mol/L和1.0×10 -6~1.0×10 -3mol/L范围内呈良好线性 ,检出限分别为2.24×10 -7mol/L和5.48×10 -7mol/L。7次测定分别含5.0×10 -4mol/L黄芩素和黄芩甙试样溶液 ,峰高的相对标准偏差分别为3.53%和4.03%。 相似文献
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L-半胱氨酸自组装膜电极对米吐尔的电催化及其分析应用 总被引:12,自引:0,他引:12
研究了米吐尔在L 半胱氨酸自组装膜修饰金电极上的电化学行为。米吐尔在该修饰电极上的CV曲线仅出现一对峰 ,其峰形对称 ,ΔEp =42mV ,氧化还原峰电流之比约等于 1,为可逆反应 ;扩散系数D =2 .2 4× 10 - 6 cm2 ·s- 1 。初步探讨了电催化机理。差分脉冲伏安法测定其氧化峰电流与米吐尔浓度在 5 .0× 10 - 7~ 2 .0× 10 - 5mol/L和 5 .0× 10 - 5~ 1.0× 10 - 3 mol/L范围内分段呈线性关系 ;相关系数分别为 0 .9987和 0 .9972 ;检测限 1.0× 10 - 8mol/L 相似文献
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本文研制了一种新型的羧基化多壁碳纳米管修饰电极作为色谱电化学检测器。实验结果表明,6 巯基嘌呤浓度在4.0×10-7~1.0×10-4mol/L范围内与其峰电流呈良好的线性关系,检出限为2.0×10-7mol/L(S/N=3)。此外,将该方法与微渗析取样技术相结合,实现了对6 巯基嘌呤(6 MP)与牛血清白蛋白(BSA)相互作用的研究,测得6 MP与BSA的结合常数和结合位点数分别为3.97×103(mol/L)-1和1.51。 相似文献
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碳纳米管修饰电极对多巴胺和肾上腺素的电分离及同时测定 总被引:17,自引:0,他引:17
研究了多巴胺 (DA)和肾上腺素 (EP)在多壁碳纳米管 (MWNT)修饰电极上的电化学性质 ,发现该修饰电极对神经递质DA和EP有显著的增敏和电分离作用。还原峰电位差达ΔEp=390mV ,可同时测定DA和EP。DA和EP的还原峰电流与其浓度分别在 2 .0× 10 -6~ 1.0× 10 -3 mol/L和 1.0× 10 -6~ 1.0× 10 -3 mol/L浓度范围内呈良好的线性关系 ;方法的检出限分别为 1× 10 -6mol/L和 5× 10 -7mol/L。由于抗坏血酸 (AA)在MWNT修饰电极上的氧化是不可逆的 ,因此利用还原峰进行测定 ,消除了AA对DA和EP的干扰 相似文献
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L-半胱氨酸自组装膜修饰电极对对氨基酚电催化氧化及其分析应用 总被引:5,自引:0,他引:5
在裸金电极上制备了L 半胱氨酸自组装膜修饰电极(L Cys/AuSAMs),研究了对氨基酚(p AP)在L Cys/AuSAMs上的电化学行为,发现该膜电极对p AP的氧化具有良好的电催化作用。氧化峰电位降低了128mV,测得p AP的扩散系数D为1.27×10-6cm2·s-1,初步探讨了电催化机理。采用水平衰减全反射 傅立叶变换红外光谱(ATR FTIR)技术对L Cys/AuSAMs进行了表征;方波伏安法(SquareWaveVoltammetry,SWV)测定p AP,其氧化峰峰电流与p AP浓度在1.0×10-8~8.0×10-8mol·L-1和1.0×10-7~2.0×10-4mol·L-1范围内呈线性关系,相关系数分别为0.9978和0.9977,检出限为2.0×10-9mol·L-1。该电极用于模拟废水样的测定,结果满意。 相似文献
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The regioselectivity of the oxidation of three monosubstituted olefins, 6-phenoxyhex-1-ene, hex-1-ene and styrene, by iodosobenzene in the presence of various Fe-, Mn- or Cr-tetraaryl-porphyrins, was studied. It was found that, besides epoxides, known products from such systems, allylic alcohols and aldehydes were formed, the latter not being derived from the corresponding epoxides. The relative importance of these reactions greatly depends upon both the metal and porphyrin constituents of the catalyst. More particularly, the competition between epoxidation and allylic hydroxylation can be efficiently controlled by non-bonded interactions between the olefin and porphyrin substituents. No hydroxylation of the aromatic rings and no oxidative dealkylation of the ether function was detected. 相似文献
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Florian Schn Lutz Greb Elisabeth Kaifer Hans‐Jrg Himmel 《Angewandte Chemie (International ed. in English)》2020,59(23):9127-9133
Cationic monoboranes exhibit a rich chemistry. By constrast, only a few cationic diboranes are known, that all are symmetrically substituted. In this work, the first unsymmetrically substituted dicationic diboranes, featuring sp2–sp2‐hybridized boron atoms, are reported. The compounds are formed by intramolecular rearrangement from preceding isomeric symmetrically substituted dicationic diboranes, a process that is catalyzed by nucleophiles. From the temperature‐dependence of the isomerization rate, activation parameters for this unprecedented rearrangement are derived. The difference in fluoride ion affinity between the two boron atoms and the bonding situation in these unique unsymmetrical dicationic diboranes are evaluated. 相似文献
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V. S. Kulikova M. M. Levitsky A. F. Shestakov A. E. Shilov 《Russian Chemical Bulletin》1998,47(3):435-437
The reaction of oxidation of 1,4-dimethylcyclohexane (DMCH) by perchloric acid at ~20 °C catalyzed by polyphenylferrosiloxane has been found. The chromatographic analysis has revealed the formation of several products, including the tertiary alcohol with 100% retention of the configuration of the initial configuration. The specific feature of the process is the following: along with the high stereospecific formation of the tertiary alcohol,cis-trans isomerization in the starting 1,4-DMCH is observed. The data obtained are discussed on the basis of the mechanism, including the formation of a ferryl intermediate with the subsequent transfer of the oxygen atom to the tertiary C?H bond of 1,4-DMCH through the intermediate complex with the five-coordinated carbon. 相似文献
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Giovanna Pressi Roberto Dal Toso Renzo Dal Monte Giovanni Carturan 《Journal of Sol-Gel Science and Technology》2003,26(1-3):1189-1193
Ajuga reptans cells are cultivated and used for production of invertase. These plant cells are immobilized by a sol-gel SiO2 membrane, which is built up directly on the cell surface by exposure to a gaseous flow of silicon alcoxide precursors. The immobilization modifies the metabolic activity of cells, resulting in a 40-fold increase in invertase production with respect of free cells. Results concerning total release of proteins, cell growth and produced invertase activity are discussed, considering the absence of breeding, induced by SiO2 immobilization, the prominent factor promoting the observed exceptional increase in invertase productivity. 相似文献
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Synthesis of arylaliphatic chlorosilanes by alkylation of aromatic compounds by alkenylchlorosilanes
Ya. Kh. Bieshev I. T. Farkhieva Yu. B. Monakov S. R. Rafikov 《Russian Chemical Bulletin》1985,34(7):1499-1501
Conclusions In combination with HCl or H2O, EtAlCl2 is an active catalyst for alkylation of aromatic compounds by alkenylchlorosilanes, and compounds of boron, titanium, and tin are inactive in this reaction.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1639–1641, July, 1985. 相似文献