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1.
过氧化氢-巯嘌呤氧化还原反应的研究及荧光分析应用   总被引:4,自引:0,他引:4  
研究了过氧化氢氧化巯嘌呤的反应条件及产物的荧光特性 ,提出了高灵敏荧光光度法测定巯嘌呤含量的新方法。在碱性介质和沸水浴加热条件下 ,过氧化氢能将巯嘌呤定量转化为 6-嘌呤磺酸钠 ,其体系的荧光强度与巯嘌呤浓度在6.0× 1 0 -8~ 1 .0× 1 0 -5mol/L范围内呈线性关系 ,检出限为 2 .4× 1 0 -8mol/L。该法已用于片剂中的巯嘌呤含量的测定。  相似文献   

2.
三维荧光光谱法连续测定苯胺、二苯胺和N-甲基苯胺   总被引:3,自引:0,他引:3  
本文比较了苯胺、二苯胺、N-甲基苯胺的二维荧光光谱和三维荧光光谱。提出了同时测定苯胺,二苯胺和N甲基苯胺的分析方法,它们的浓度分别在2.0×10~(-7)~5.0×10~(-6)mol/L,9.0×10~(-8)~7.4×10~(-6)mol/L,1.3×10~(-7)~2.0×10~(-8)mol/L范围内有良好的线性关系,检出限为1.0×10~(-7)mol/L,8.0×10~(-9)mol/L,1.0×10~(-7)mol/L.相对标准偏差分别为5%,7%,7%.此方法用于混合样品和工业废水的分析,获得较满意的结果.  相似文献   

3.
在酸性条件下,甲醛与高锰酸钾能够产生较弱的化学发光,而巯嘌呤的存在能够大大地增强该化学发光强度。在一定浓度范围内,增加的发光强度与巯嘌呤的浓度呈良好的线性关系,由此建立了一种测定巯嘌呤的流动注射化学发光方法。方法的检出限为8.7×10-9 g/mL,线性范围为1.0×10-8~1.0×10-6 g/mL,相对标准偏差为3.1%(c=5.0×10-7 g/mL,n=11)。  相似文献   

4.
本文研究了钴(Ⅱ)-5-Br-PADAP体系的吸附伏安法。方法的线性范围为1×10~(-9)~5×10~(-7)mol/L。,检测下限为4×10~(-10)mol/L。并将此法应用于人发中痕量钴的测定。  相似文献   

5.
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。  相似文献   

6.
硅钼杂多酸示波极谱法测定抗坏血酸   总被引:5,自引:0,他引:5  
王长发  马俊义 《分析化学》1992,20(6):710-713
本文研究了硅钼杂多酸与抗坏血酸的反应,发现其产物在示波极谱上于~1.12V(vs.SCE)产生灵敏吸附波,导数波高与抗坏血酸浓度在1×10~(-7)mol/L~4×10~(-5)mol/L有线性关系。检测限为5×10~(-8)mol/L。本法应用于针剂,片剂及柑桔中抗坏血酸的测定,得到满意结果。  相似文献   

7.
土豆组织-碳糊电极的研制及应用   总被引:5,自引:1,他引:4  
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。  相似文献   

8.
新吖啶酯发光剂测定过氧化氢的研究   总被引:3,自引:0,他引:3  
张帆  庄惠生 《分析化学》1992,20(3):342-344
本文报道了新发光剂氟磺酸-10-甲基-9-(对甲酰基苯基)羧酸吖啶酯测定饮用水和降水中H_2O_2的研究。该方法无需任何催化剂,选择性好,灵敏度高,检测限达1.2×10~(-9)mol/L,线性范围宽(3×10~(-9)~1×10~(-2)mol/L),测定5×10~(-9)mol/L和6.6×10~(-7)mol/L H_2O_2时,相对标准偏差分别为3.2%和1.6%。  相似文献   

9.
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。  相似文献   

10.
青椒籽浆-碳糊生物电极的研制及应用   总被引:3,自引:0,他引:3  
本文研制了青椒籽浆-碳糊生物电极,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L-抗坏血酸,线性范围为1.15×10~(-5)~1.24×10~(-4)mol/L,检测下限可达到9.87×10~(-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12d。  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.
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   

18.
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   

19.
20.
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   

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