土豆组织-碳糊电极的研制及应用

本文研制了土豆组织-碳糊电极,并探讨了电极的性能及实用性。实验表明,该电极可用于伏安法快速检测多巴胺。线性范围为5.3×10~(-8)～9.8×10~(-5)mol/L。检测下限达到1.8×10~(-6)mol/L。电极具有良好的重现性和选择性。响应时间短,使用寿命为20天。     

Nafion-甲基紫精修饰电极抗坏血酸氧化酶生物传感器的研究

本文用Nafion-甲基紫精修饰电极为基底,以牛血清白蛋白和戊二醛为交联剂,将抗坏血酸氧化酶固定在电极上,制成修饰电极抗坏血酸氧化酶生物传感器。用这种生物传感器测定人体血清中抗坏血酸,线性范围在7.5×10~(-4)～7.5×10~(-7)mol/L之间,响应时间为5s,检测下限为2.5×10~(-7)mol/L。该传感器具有选择性好、灵敏度高和响应时间短等特点。     

毛细管电泳-电化学检测测定茶叶中咖啡因、表儿茶素和抗坏血酸

高效毛细管电泳电化学检测同时测定了6种茶叶中的咖啡因、表儿茶素和抗坏血酸的含量,考察了实验参数对分离、检测的影响。在最佳实验条件下,以300 靘直径的碳圆盘电极为检测电极,检测电极为1.20 V(vs.SCE),在25 mmol/L硼酸盐25 mmol/L磷酸盐(pH 7.6)的混合运行缓冲液中,上述各组分在16 min内能完全分离。咖啡因、表儿茶素和抗坏血酸在2×10-3mol/L～１×10-5 mol/L、5×10-5mol/L～5×10-7mol/L、2×10-4 mol/L～1×10-5mol/L范围内呈线性关系,检测下限分别为6×10-6mol/L、4×10-7mol/L和1×10-6mol/L。该法直接用于茶叶中咖啡因、表儿茶素和抗坏血酸的测定,结果令人满意。     

碳棒涂膜式PVC膜离子选择电极的研究 1.丁基罗丹明B-AuCl_4~-离子选择电极的研制和应用

本文研制了以丁基罗丹明B-AuCl_4~-为电活性物质的碳棒涂膜式PVC膜金离子选择电极。电极对AuCl_4~-离子在1×10~(-3)-7.1×10~(-7)mol/L范围内呈能斯特响应,检测限为5.0×10~(-7)mol/L,级差为58mV(20℃)。电极内阻为0.1MΩ,响应时间小于30秒。电极稳定性、重现性良好。该电极结构简单,制作、储存方便,价格低廉,已成功用于矿样中金的测定。     

聚氯乙烯膜曲马多选择电极的研制与应用

报道一种以曲马多与四苯硼的缔合物为电活性物的新型PVC膜曲马多选择电极,电极的Nernst响应范围为1．0×10~(－2)~2．1×10~(－5)mol/L;斜率为57mV/pC;检测限为7．2×10~(-6)mol/L。此电极响应迅速,重视性好,用此电极以标准曲线法对药物中的曲马多进行了测定,此法简便,结果与紫外分光光度法相符。     

吸附溶出催化伏安法测定人参中的锗

本文提出了利用吸附溶出催化伏安法测定人参中锗的方法。最佳体系为:2.5×10~(-2)mol/LH_2O_2、2.0×10~(-2)mol/L邻苯二酚、2.0×10~(-3)mol/L H_2SO_4。线性范围为2.0×10~(-9)～2.0×10~(-7)mol/L。当富集时间为4 min时,最低检测浓度为4.0×10~(-10)mol/L。此法己成功地应用于测定人参中的锗。     

丝氨酸织组膜电极的研究

利用猪肝组织膜配合氨气敏电极,研制了丝氨酸生物催化传感电极。丝氨酸浓度的测定范围为5.1×10~(-5)～3.2×10~(-3)mol/L,检出限为3.1×10~(-5)mol/L。研究和讨论了电极的最佳工作条件,并测定了实验条件下酶催化反应的米氏常数Km。该电极用于合成样品分析,效果满意。     

Eastman-Kodak AQ膜修饰电极阴极溶出伏安法测定痕量铁

本文用热处理法成功地制备了性能稳定的Eastman-Kodak AQ/GC修饰电极,对Fe~(3+)/Fe~(2+)及其络合阳离子在该电极上的行为进行了研究。表明AQ膜对Fe~(3+)和Fe~(2+)具有相近的交换能力,可用于Fe~(3+)或Fe~(2+)及其总量的阴极溶出伏安法测定。线性范围分别为2.0×10~(-7)～2.2×10~(-5)mol/L(Fe~(3+))和5.0×10~(-7)～2.0×10~(-5)mol/L(Fe~(2+)),检出限为1.0×10~(-7)mol/L(Fe~(3+))。文中对电极反应和再生进行了探讨。     

混合香蕉组织碳糊生物微电极的研究及在活体分析中的应用

我们研制了混合香蕉组织碳糊生物微电极,用于神经递质多巴胺(DA)的测定,研究了DA在该电极上的伏安特性及最佳工作条件。该电极选择性好,可抗256倍维生素C(V_(?))的干扰;灵敏度高,检出下限为3.3×10~(-8)mol/L。用于活体分析鼠脑纹状体中DA,线性范围为1.9×10~(-6)～1.3×10~(-4)mol/L(静置时间为10s)。     

以聚氯乙烯-双硫腙-铜络合物为载体的长寿命硫氰酸根离子选择电极

报道了以PVG-双硫腙（DTZ）-Cu（Ⅱ）,PVC-DTZ-Cu（Ⅰ）为载体制备了性能良好的SCN-离子电极,其选择性次序为SCN~-》ClO_4~->Sal~-》NO_3~-~Cl~->PO_4~(2-)。16℃时,膜组成为PVC－DTZ-Cu（Ⅰ）：PVC：邻硝基苯基辛醚（o-NPOE）＝12∶22∶66的SCN~-离子电极,在0．02mol/LHCl体系中,在1×10~(-2)~5×10~(－6)mol/LSCN~-浓度范围呈能斯特响应,斜率为58±2mV/dec,检测限为2×10~(-6)mol/L;膜组成为PVC-DTZ-Cu（Ⅱ）∶PVC∶o-NPOE∶四苯硼酸钾（KTPB）为8∶22∶55∶15的电极,在0．01mol/LHAc-NaAc缓冲体系中,在10~(-2)~2×10~(-6)mol/LSCN~-浓度范围呈线性响应,斜率为54∶1mV/dec,检测限为8×10~(－7)mol/L.研究了阴离子与载体作用的机理,表明SCN~-与载体中铜原子直接作用。电极应用于废水中SCN~-的测定,结果令人满意。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

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.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

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%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.