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1.
采用目标因子分析技术与导数光度法相结合,同时测定镍、铜、锌。用PAR作显色剂,三种离子在一阶导数光谱最大吸收波长处的摩尔吸光系数分别为3.8×10 ̄5,2.7×10 ̄5和5.5×10 ̄5L·mol ̄(-1)·cm ̄(-1)比基本光谱最大吸收波长处的摩尔吸光系数分别提高5.8、7.1和5.7倍。用于人工合成样的分析,结果良好。  相似文献   

2.
铜(Ⅱ)和锌(Ⅱ)分别在0.1mol/LKH_2PO_4-Na_2HPO_4缓冲溶液(pH6.5)和0.25mol/LNH_4Cl溶液中,与氟哌酸形成良好的络合吸附波,峰电位分别为-0.26V和-1.28V(vs;SCE);络合比分别为1:3和1:2;峰电流与铜(Ⅱ)和锌(Ⅱ)的浓度均在4.0×10 ̄(-7)~5.0×10 ̄(-6)mol/L范围内呈线性关系,检测限分别为7.0×10 ̄(-8)和5.0×10 ̄(-8)mol/L。用线性扫描和循环伏安法等手段研究体系的行为,表明均具吸附性,而铜(Ⅱ)-氟哌酸体系属络合物中铜(Ⅱ)的两电子还原的可逆过程。  相似文献   

3.
佝偻病患儿发中微量元素观察   总被引:1,自引:0,他引:1  
对48例佝偻病患儿发中锌、铅、铜3种元素用ICP-AES法测定,同时采患儿指端血用超微量分析仪测定血钙、磷、碱性磷酸酶(AKP),与正常组对比,以探讨佝偻病与微量元素的关系.结果表明:佝偻病患儿发锌、血钙、血磷低于对照组,发锌100.36×10-6±51.88×10-6,167.76×10-6±113.52×10-6,P<0.01;血钙4.77±0.86mg/dL,5.29±0.57mg/dL,P<0.05;血磷8.21±1.06mg/dL,9.45±1.44mg/dL,P<0.01,发铅、铜/锌比值及AKP高于对照组,分别为发铅46.7×10-6±26.7×10-6,26.79×10-6±11.6×10-6,P<0.01;铜/锌0.2589±0.187,0.1442±0.106,P<0.05;AKP36.43±24.65u,25.18±5.79u,P<0.05。提示婴幼儿体内锌含量不足及铅过高是引起佝偻病的原因之一。在防治佝偻病时,应补充微量元素锌.  相似文献   

4.
本文研究了新水溶性卟啉试剂5,10,15,20-四(3-溴-4-磺酸苯基)卟啉[T(3-BrP)PS_4与铜的显色反应。在pH3,铜与5,10,15,20-四(3-溴-4-磺酸苯基)卟啉形成1:1的稳定配合物。此配合物的最大吸收波长位于412.8nm,摩尔吸光系数为2.61×10 ̄5L·mol ̄(-1)·cm ̄(-1)。铜量在0~3.0μg/25mL范围内符合比尔定律,工作曲线回归方程为y=0.00943、+0.167x,相关系数为r=0.9997。方法有较高的灵敏度和较好的选择性,直接用于大米和茶叶中痕量铜的测定,结果与AAS法一致。  相似文献   

5.
极谱法快速同时测定锌电解液中微量铜、镉、钴   总被引:7,自引:0,他引:7  
铜、镉、钻在了丁二酮肟-氯化铵-柠檬酸钠-HAc-NaAc体系中有灵敏的极谱波。其峰电位分别为-0.24V、- 0.79V和-0.93V,线性范围分别为4 × 10~(-6)~ 4 × 10~(-3)、5 × 10~(-6)~ 5×10~(-3)、1×10~(-7)~1×10~(-4)g/L,检测限分别为2×10~(-6)、4 × 10~(-6)和5×10~(-8)g/L。方法无需预处理直接用于锌电解液中微量铜、镉、钴的测定,结果令人满意。  相似文献   

6.
在含有0.05mol/LHAc-NaAc(pH5.6)、0.1mol/LKCl和1.5×10 ̄(-5)mol/L茜素紫的溶液中,镓(Ⅲ)-茜素紫络合物在单扫示波极谱仪上产生一灵敏的导致极谱波,峰电位在-1.11V(vs.SCE),峰电流与镓(Ⅲ)浓度在2.0×10 ̄(-8)~2.0×10 ̄(-6)mol/L范围内呈线性关系,检测限达1×10 ̄(-8)moL/L机理研究表明,峰电流是由吸附在电极表面的络合物中的中心离子和配位体同时还原而产生的。方法已应用于铝合金中镓的测定,结果满意。  相似文献   

7.
高锰酸钾-抗坏血酸化学发光体系测定抗坏血酸   总被引:2,自引:0,他引:2  
本文研究了高锰酸钾-抗坏血酸化学发光体系,建立了测定抗坏血酸的化学发光分析新方法。线性响应的浓度范围为5.0×10 ̄(-7)mol/L~4.0×10 ̄(-5)mol/L检出限为3.0×10 ̄(-7)mol/L对2.5×10 ̄(-6)mol/L抗坏血酸进行10次平行测定,相对标准偏差为1.6%。考察了22种物质的干扰情况。用于维生素C片剂及注射液中抗坏血酸含量测定,结果令人满意。  相似文献   

8.
报告了测定痕量铜的一种新方法。在0.01mol/LHAc-NaAc溶液中,铜和乙醛酸缩氨基硫脲(GATSC)形成的配合物产生一很灵敏的还原峰,峰电位是-0.33V(vs·SCE),铜的浓度在1.0×10-8~2.0×10-6mol/L范围内成直线关系,检测限为3.0×10-9mol/L,该法用于测定水中痕量铜,结果令人满意。  相似文献   

9.
野外快速测定化探样品中的微量砷   总被引:3,自引:0,他引:3  
薛光 《分析试验室》1994,13(6):26-27
提出了一个野外快速测定化探样品中微量砷的新方法。该法采用砷化氢富集,以硫酸银泡塑班点法进行测定方法的检出限为0.5×10^-6g,测定范围为0 ̄10μg/10mL As。  相似文献   

10.
王桂芬  朴元哲 《分析化学》1998,26(12):1490-1493
应用循环伏安法、微分脉冲伏安法对多菌灵在破碳电极上的电化学行为及其测定进行了研究。在pH=9.0的2mol/L NH3-NH4Cl底液中,对其进行循环伏安扫描,发现于0.61V(vs.Ag/AgCl)产生一灵敏的氧化峰。微分脉冲伏安法殉菌灵的检测限为4×10^-8mol/L。多菌灵的浓度在5.0×10^-7 ̄1.0×10^-5mol/L间与微分脉冲伏安峰电流呈线性关系(r=0.9942)。对于1×  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
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   

13.
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   

14.
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   

15.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

16.
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   

17.
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   

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.
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   

20.
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   

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