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1.
邱瑾 《分析化学》1998,26(5):552-555
建立了微生物代谢中硫酸根和硫代硫酸根的毛细管电泳分析方法.在选定实验条件下,各种阴离子(S2O2-3、SO2-4、CI-、NO-3、PO3-4)在4 min内达到完全分离,其中 S2O2-3和SO2-4迁移时间的相对标准偏差小于1%,峰面积的相对标准偏差小于5%.测定了4种菌株分别在两种培养基中的S2O2-3和SO2-4浓度随培养时间的变化.结果表明,其中一菌株在SK基中对S2O2-3有明显的氧化作用.  相似文献   

2.
NH4ZnPO4的非水合成与晶体结构   总被引:3,自引:2,他引:3  
从非水体系中制得NH4ZnPO4单晶,并用X线测定了晶体结构;晶体属六方晶系,P63空间群,晶胞参数;a=1.0688(2)nm,c=8706(2)nm,Z=8,Dc=2.751g.cm^-3,结构中的锌和磷均为四面体本位,且严格交替排列,无Zn-O-Zn和P-O-P联结方式。  相似文献   

3.
杨志 《分析化学》1998,26(5):542-544
在金电极上,用电化学方法将单缺位Dawson型磷钨杂多酸盐a2-K10P2W17O6115H2O的阴离子(P2W17)掺杂到聚吡咯(PPy)薄膜中,制成PPy/P2W17/Au的H2O2传感器。研究了它对 H2O2电还原过程的催化机理.其 ipe与 CH2O2在 6.0× 10-5~8. 8×10-4 mol/L和8.8×10-4~6.0×10-3mol/L范围内呈良好的线性关系,检测下限为4.0×10-5mol/L。用于模拟水样中H2O2的测定,结果较满意.  相似文献   

4.
测定了三元体系La(ClO4)3-OCBAAP-H2O在30℃时的溶解度.结果表明,该体系有一个新固相(不一致溶解化合物)La(OCBAAP)4(ClO4)3·6H2O形成.参考该体系溶度图确定合成条件,合成了系列化合物Ln(OCBAAP)4(ClO4)3·nH2O(Ln=La,n=6;Ln=Pr,Nd,Sm,Gd,Yb,n=2).通过化学分析、元素分析、TG-DTG、IR和密度对化合物进行了表征,计算了La(OCBAAP)4(ClO4)3热分解过程各阶段的表观活化能.  相似文献   

5.
王晓晗  黄仲涛 《分子催化》1998,12(4):285-291
用正戊醇和仲醇还原VOPO4.2H2O,以制备正丁烷氧化顺酐的V-P-O催化剂前驱物VOHPO4.0.5H2O,并用XRD,TG,SEM对共进行了表征。结果表明,由正戊醇还原VOPO4.2H2O合成的前驱物VOHPO4.0.5H2O的XRD,在(22)晶面衍射强度较强;而由仲戊醇合成的前驱物VOHPO4.0.5H2O的XD,在(001)晶面衍射强度较强。正戊醇还原VOPO4.2HO2合成的前驱物V  相似文献   

6.
本文研究了Cu(Ⅱ)-PEG(聚乙二醇-2000)-Zincon(锌试剂)-(NH4)2SO4体系的析相光度法并应用于测定Cu(Ⅱ)。最宜酸度为pH5.5~8.5(KH2PO4-K2HPO4)缓冲溶液)其络合物的最大吸收位于610nm,表观摩尔吸光系数为4.0×10^4L.mol^-1.cm^-1,Cu(Ⅱ)浓度在0~1.5mg/L范围内服从比尔定律,铜与Zincon形式组成为1:2的稳定的蓝色络  相似文献   

7.
C5烃中双环戊二烯过氧化物的分光光度测定   总被引:1,自引:0,他引:1  
王兴国  马兰萍 《分析化学》1996,24(3):356-359
本报道了C5烃中双环戊二烯过氧化物(PDCPD)快速准确的分析方法。在HOC2H4OCH3-H2O介质中,PDCPD与KI反应生成I3^-而I3^-与PDCPD的量成正比,在λmax=352nm处可进行PDCPD的光度测定,测定下限为3.2×10^-5mol/L,SD=0.34,RSD=1.40%。  相似文献   

8.
张光  张林林 《分析化学》1997,25(1):79-81
报道以5-(5-硝基-2-吡啶偶氮)-2,4-二氨基甲苯(5-NO2-PADAT_作为测定钌的分光光度法。在40%乙醇存在下PH4.0-6.5乙酸-乙酸钠缓冲溶液中5-NO2-PADAT与Ru(Ⅱ)形成稳定的红色络合物。该络合物的无机酸作用下,可转变为另一型人有较高吸收特性的络合物,适宜酸度范围分别为0.12-2.0mol/LHCl,0.12-1.2mol/LHClO4,0.12-1.0mol/L  相似文献   

9.
氢化物发生ICP-AES法测定药用植物中的痕量锗   总被引:6,自引:0,他引:6  
本文应用氢化物发生ICP-AES法研究了药用植物样品中痕量锗的测定方法,系统地研究了ICP-AES仪器参数及氢化物发生条件对锗谱线信背比的影响,考察了13种共存元素的干扰,并比较了植物样品的3种前处理方法。选定H3PO4-HNO3-H2O2消化,在3mol/LH3PO4介质中,以15g/LNaBH4还原,测定药用植物样品中的锗,相对标准偏差≤2.9%,回收率为94%~103%。方法检出限达0.13μg/L。  相似文献   

10.
本文采用单柱离子色谱系统测定了C2O^2-4,以1.3mmol/L葡萄糖酸钠/1.3mmol/L硼砂为淋洗液测定C2O^2-4,8常见阴离子Cl^-,NO^-3,HPO^2-4,SO^2-4不干扰测定,C2O^2-4的检出限为0.57mg/L,相对标准偏差为1.07%,工作曲线的线性范围为0.57-500mg/L,应用本方法测定了加C2O^2-4的自来水样,C2O^2-4的回收率为99.52%。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
19.
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 CuI 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).  相似文献   

20.
(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.  相似文献   

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