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1.
碘的凝胶色谱测定方法   总被引:6,自引:1,他引:6  
丁朝武  李华斌 《分析化学》1997,25(5):586-589
建立了碘折凝胶色谱测定方法。色谱条件为:Shim-pack DIOL-150柱;流动相甲醇0.01mol/L H3PO4(10:90)流速为1.2mL/min;柱温为35℃,检测波长为224nm;线性范围是0.010-1.0mg/L,相关系数为0.9993,检测限为0.001mg/L,相对标准偏差为1.2%-4.6%;回收率为91%-98%。所建立的方法已用于食盐,尿,系带等样品的测试,均取得较好  相似文献   

2.
偏最小二乘催化极谱法同时测定铂,钯,铑   总被引:6,自引:0,他引:6  
应用M273A电化学系统中的线性扫描技术,确定了0.75mol/LH2SO4-1.5%NH4Cl-2.8mmol/L(CH2)6N4-0.0025%N2H4.H2SO4为偏最小二乘极谱法同时测定Pt、Pd、Rh的最佳极谱体系。Pt、Pd、Rh的线性范围为3.2mg/L、0-15.0mg/L和0-1.0mg/L。模拟样品及实际样品的回收率在90.3-107.7%之间。  相似文献   

3.
铁,钴,镍的反相高效液相色谱分离和测定   总被引:4,自引:0,他引:4  
丁朝武  李华斌 《分析化学》1998,26(10):1284-1284
1引言建立了用反相高效液相色谱同时测定铁、钴、镍的分析方法并对Men+-二硫腙(DZ)体系的色谱行为进行了探索。较之萃取进样更快速、简便。测定条件为:Shim-PackCLC-ODS(φ6×150mm,5μm);流动相:甲醇:水:三氯甲烷(含1%三乙胺)(80:10:10);流速1mL/min;柱温35℃;检测波长254n。线性范围0.01-2.0mg/L;相关系数r=0.999l~0.9998;检测限为0.0023~0.0050mg/L;相对标准偏差为1.8%-2.7%;回收率为96%-104…  相似文献   

4.
用石墨炉原子吸收法测定水质中微量砷,硒的探讨   总被引:4,自引:0,他引:4  
采用石墨炉原子吸收法测定水中微量砷,硒,经大量实验条件摸索,选择不同仪器分析工作条件,找出了最佳升温程序条件,特别是原子化时气流控制,使分析方法的检出限降低为:As0.6μg/L,Se0.5μg/L。线性范围;As0.000-0.120mg/L,Se0.000-0.024mg/L;精密度,相对标准偏差分别为:As1.26%,3.67%,Se2.56%,4.57%,回收率为:As98.0%-110.  相似文献   

5.
络天青S—CPB—Brij35胶束增溶吸光光度法测人发中微量铜   总被引:5,自引:0,他引:5  
在阳离子表面活性剂CPB和非离子表面活性剂Brij35存在下,pH7.5的弱碱性介质中,二价铜离子与络天青S形成灵敏度高的1:2络合物。应用吸光度法测定人发中微量铜,铜含量在0.02~2.0mg·L^-1遵守比耳定律,方法检出限为限为0.01mg·L^-1,平均回收主继100.5%±0.21%,RSD为0.21%。此法用于人发中微量铜的测定。结果满意。  相似文献   

6.
氢化物—无色散原子荧光法测定螺旋藻胶囊中的微量硒   总被引:18,自引:2,他引:18  
邹菁  张平 《分析试验室》1998,17(5):84-86
研究了氢化物原子荧光法测定螺旋藻胶囊中的微量硒,系统地考察了消解体系;确定了最佳测定条件,共存元素的影响及干扰的消除,硒的检出限为1.3×10^-3mg/L,线性范围为0-0.25mg/L,回收率在97.5%-102.3%之间,RSD小于5%。  相似文献   

7.
荷移反应用于氨苄青霉素的测定   总被引:9,自引:0,他引:9  
研究了氨苄青霉素与对苯醌的荷移反应,确定了反应条件。在PH4.4-5.0的醋酸-醋酸钠缓冲溶液中形成1:1络合物,其λmax=472nm。氨苄青霉素三水合物浓度在10-125mg/L范围地线性关系;当浓度为50mg/L时相对标准偏1.8%;表观摩尔吸光系数为2.64×10^3L.mol^-1.cm^-1。应用拟定的方法测定药物制剂含量,结果与药典方法一致。回收率在96%以上。  相似文献   

8.
反相高效液相色谱法测定氟离子   总被引:8,自引:0,他引:8  
丁朝武  李华斌 《分析化学》1998,26(3):369-369
1引言本文建立了反相液相色谱测定氟离子的方法,与分光光度法相比,可将含氟络合物与试剂分离开,大大提高了测定的灵敏度和选择性。测定条件为Shim-PackCLC-ODS(6×150mm5u);流动相:甲醇-水(18:82);流速:1mL/min;柱温:35℃;检测波长:566nm。线性范围0.050~1.0mg/L;相关系数r=0.9991;检测限为0.001mg/L;相对标准偏差为1.9%~2.7%;回收率为97%~98%。本方法初步用于矿泉水和食盐等样品的测定,均取得较好的效果。2实验部分2.…  相似文献   

9.
王尊本  王润棠 《分析化学》1999,27(3):312-315
在酸性介质中,铁和钯分别与亚硝基R盐络合形成绿色的Fe-NRS和红色的Pd0NRS,利用一阶导数分光光度法在水相中同时测定Fe和Pd。结果证明,两种络合物的摩尔吸光系数分别为1.94×10^4L.mol^-1.cm^01(对铁)和1.63×10^4L.mol^-1.cm^1(对钯);线性范围分别为0-5.6mg/l(对铁)和0-7.0mg/L(对钯);相对标准偏差均小于2.0%;回收率为965-1  相似文献   

10.
KBrO3—KBr紫外分光光度法测定痕量水杨酸   总被引:5,自引:0,他引:5  
研究了HCl溶液中KBrO3-KBr紫外分光光度法测定水杨酸的条件,建立了测定痕量水杨酸的新方法。结果表明,在0.6mol/LHCl,3*10^-5mol/LKBrO3,5*10^-4mol/LKBr,6*10^-4mol/lKI溶中测定水杨酸,其线性范围为0.2-4.0mg/L,表观摩尔吸光系数为1.9*10^-4L.mol^-1.cm^-1,Sandell为7.3μg/cm^2。sg if e  相似文献   

11.
The extraction of copper with calixarenes was researched by comparing the results from calix[4]-,calix[6]-and calix[8]-arenes.Hie extraction ability increased as the order:calix [4]-> calix[8]-> calix[6]-arenes,with the binding ratio being 1:1.The extraction mechanism was also discussed,and itsequation Cu(NH3)42 H2L(0)Cu(NH3)4L(0) 2H and the extraction equilibrium constants(Ker)for calix[6]-and calix[8]-arenes were obtained respectively.  相似文献   

12.
The coordination chemistry of the tetradentate pyridyl-thiazole (py-tz) N-donor ligand 6,6'-bis(4-phenylthiazol-2-yl)-2,2'-bipyridine (L1) has been investigated. Reaction of L1 with equimolar copper(II) ions results in the formation of the single-stranded mononuclear complex [Cu(L1)(ClO4)2] (1), whereas reaction with copper(I) ions results in the double-stranded dinuclear helicate [Cu2(L1)2][PF6]2 (2). Both complexes were characterized by X-ray crystallography, UV-vis spectroscopy, and electrospray ionization mass spectroscopy (as well as 1H NMR spectroscopy for diamagnetic 2). Complex 2 is redox-active and, upon one-electron oxidation, forms the stable tricationic mixed-valence helicate [Cu2(L1)2]3+ (3). This species can also be prepared in situ by combining [Cu(MeCN)4][BF4], [Cu(H2O)6][BF4]2, and L1 in a 1:1:2 ratio in nitromethane. X-ray crystallographic analysis of 3 provides structural evidence for the presence of an internuclear Cu-Cu bond, with an even distribution of spin density across the two Cu centers. Room-temperature UV-vis spectroscopy is consistent with this finding; however, frozen-glass EPR spectroscopic investigations suggest solvatochromic behavior at 110 K, with the [Cu2]3+ core varying from localized to delocalized depending on the solvent polarity.  相似文献   

13.
提出一种以亚甲基二膦酸(MDPA, H4L)为主配位剂的无氰镀铜体系. 采用pH 电位滴定法分别测定MDPA的四级解离常数和MDPA-Cu(II)的稳定常数, 并比较MDPA-Cu(II)和羟基乙叉二膦酸(HEDPA)-Cu(II)的循环伏安曲线和阴极极化曲线. 结果表明: MDPA各级解离常数为, pK1=1.86, pK2=2.65, pK3=6.81, pK4=9.04;MDPA与Cu2+形成分级配合物的稳定常数为, pKML=10.65, pKML2 = 5.59, pKML3 = 2.50; 随着pH升高, 形成的配合物依次为, Cu(H3L)2、[Cu(H3L)(H2L)]-和[Cu(H2L)2]2-; 当pH在7-10 时, MDPA较HEDPA更易与Cu2+配位. 当pH=9 时, MDPA碱性镀铜体系阴极主要发生的是[Cu(H3L)(H2L)]-和[Cu(H2L)2]2-还原生成铜的过程; 在10 °C,MDPA体系的铜配位化合物还原生成铜的电位比HEDPA体系负移, 扩散速度更快.  相似文献   

14.
A tetranuclear mixed ligand copper(II) complex of a pyrazole containing Schiff base and a hydroxyhexahydropyrimidylpyrazole and copper(II) and nickel(II) complexes of the Schiff base having N-donor atoms have been investigated. A 2 equiv amount of 5-methyl-3-formylpyrazole (MPA) and 2 equiv of 1,3-diamino-2-propanol (1,3-DAP) on reaction with 1 equiv of copper(II) nitrate produce an unusual tetranuclear mixed ligand complex [Cu4(L1)2(L2)2(NO3)2] (1), where H2L1 = 1,3-bis(5-methyl-3-formylpyrazolylmethinimino)propane-2-ol and HL2 = 5-methyl-3-(5-hydroxyhexahydro-2-pyrimidyl)pyrazole. In contrast, a similar reaction with nickel(II) nitrate leads to the formation of a hygroscopic intractable material. On the other hand, the reaction involving 2 equiv of MPA and 1 equiv each of 1,3-DAP and various copper(II) salts gives rise to two types of products, viz. [Cu(T3-porphyrinogen)(H2O)]X2 (X = ClO4, NO3, BF4 (2)) (T3-porphyrinogen = 1,6,11,16-tetraza-5,10,15,20-tetrahydroxy-2,7,12,17-tetramethylporphyrinogen) and [Cu(H2L1)X]X x H2O (X = Cl (3), Br (4)). The same reaction carried out with nickel(II) salts also produces two types of compounds [Ni(H2L1)(H2O)2]X2 [X = ClO4 (5), NO3 (6), BF4 (7)] and [Ni(H2L1)X2] x H2O [X = Cl (8), Br (9)]. Among the above species 1, 3, and 5 are crystallographically characterized. In 1, all four copper atoms are in distorted square pyramidal geometry with N4O chromophore around two terminal copper atoms and N5 chromophore around two inner copper atoms. In 3, the copper atom is also in distorted square pyramidal geometry with N4Cl chromophore. The nickel atom in 5 is in a distorted octahedral geometry with N4O2 chromophore, where the metal atom is slightly pulled toward one of the axial coordinated water molecules. Variable-temperature (300 to 2 K) magnetic susceptibility measurements have been carried out for complex 1. The separations between the metal centers, viz., Cu(1)...Cu(2), Cu(2)...Cu(2)A, and Cu(2)A...Cu(1)A are 3.858, 3.89, and 3.858 A, respectively. The overall magnetic behavior is consistent with strong antiferromagnetic interactions between the spin centers. The exchange coupling constants between Cu(1)...Cu(2) and Cu(2)...Cu(2A) centers have turned out to be -305.3 and -400.7 cm(-1), respectively, resulting in a S = 1/2 ground state. The complexes are further characterized by UV-vis, IR, electron paramagnetic resonance, and electrochemical studies.  相似文献   

15.
在非离子型微乳液(OP/n-C5H11OH/n-C7H16/H2O)存在下,Cu2+与硫氰酸盐形成络阴离子[Cu(SCN)4]2-,在pH 3.6乙酸盐缓冲溶液中,该络阴离子再与乙基紫(EV)形成吸附型离子络合物,该络合物的组成为[Cu(SCN)4]2-:EV=1:2,最大吸收波长为660nm,表观摩尔吸光系数ε660为1.08×l05L.mol-1.cm-1,Cu2+含量在1.7~18.0μg/50 mL范围内符合比尔定律,检出限为0.5μg/50 mL,用该方法测定了钢中的铜,相对标准偏差小于2%。  相似文献   

16.
The N,N',S-donor ligand 4-methoxy-3,5-dimethyl-2-((3-(2-(methylthio)phenyl)-1H-pyrazol-1-yl)methyl)pyridine (L) was prepared from 2-(chloromethyl)-4-methoxy-3,5-dimethylpyridine hydrochloride and 3-(2-(methylthio)phenyl)-1H-pyrazole. The Cu(I) complexes [Cu2(L)2CH3CN][Cu(L)CH3CN](BF4)3 (1), [Cu(L)PPh3]BF4 (2), and [Cu6(L)2(C6F5S)6] (3) were prepared and characterized by X-ray crystallography (PPh3=triphenylphosphine, C6F5S-=pentafluorothiophenolate). The unit cell of compound 1 consists of cocrystallized mononuclear and dinuclear entities in which all of the copper atoms exhibit distorted tetrahedral coordination. Compound 2 is monomeric with L bound in the kappa3-N,N',S mode and a PPh3 molecule that completes the coordination environment. Compound 2 presents a fluxional behavior in CDCl3 solution due to the boat inversion of the six-membered N,N' chelate ring (DeltaH=+43.6(3) kJ mol(-1), DeltaS=-16(1) J mol(-1) K(-1)). Crystallization of 3 in acetonitrile leads to a polynuclear structure that contains a CH3CN molecule coordinated to one of the copper atoms: [Cu6(L)2(C6F5S)6CH3CN] (3a). The core of 3a partially resembles a {Cu4S6} adamantane-like moiety, the only difference being that the Cu-NCCH3 interaction leads to the opening of the cluster by disrupting a Cu-Cu interaction. Part of this assembly is found in the yeast metallothionein copper(I)-cysteinate core whose crystal structure has recently been reported. Two additional [Cu(L)]+ peripheral moieties interact with the cluster by means of bridging thiolates. ESI-mass spectrometry, conductivity measurements, and 1H/19F pulsed gradient spin echo (PGSE) NMR experiments suggest that 3a dissociates in acetonitrile solution: 3a+CH3CN-->[Cu4(C6F5S)6]2-+2[Cu(L)CH3CN]+. The stability of the cluster with respect to the hypothetical mononuclear species, [Cu(L)(C6F5S)], is confirmed by DFT calculations (B3LYP), which illustrate the exergonic character of the reaction: 6[Cu(L')(C6H5S)]-->[Cu6(L')2(C6H5S)6]+4L' (DeltaG298=-58.6 kJ mol(-1), where L' and C6H5S- are simplified models for L and C6F5S-, respectively). The energetics pertinent to the ionic dissociation of the cluster in acetonitrile is computed using the polarizable continuum model (PCM) approach.  相似文献   

17.
Neutral trinuclear (triangular) copper(II) complexes of type [Cu3L3] incorporating the 1,4-aryl linked bis-beta-diketonato bridging ligands, 1,1-(1,4-phenylene)-bis(butane-1,3-dione) (H2L2), 1,1-(1,4-phenylene)-bis(pentane-1,3-dione) (H2L3) and 1,1-(1,4-phenylene)-bis(4,4-dimethylpentane-1,3-dione) (H2L4) have been demonstrated to react with selected heterocyclic nitrogen donor bases to generate extended supramolecular architectures whose structures have been confirmed by X-ray diffraction. Thus on reaction with 4,4'-bipyridine (bipy), [Cu3(L2)3] yields polymeric structures of type {[Cu3(L2)3(bipy)(THF)] x 2.75THF}n and {[Cu3(L2)3(bipy)(THF)] x bipy x 0.75THF}(n) while with pyrazine (pyz), {[Cu3(L2)3(pyz)] x 0.5THF}n was obtained. Each of these extended structures contain alternating triangle/linker units in a one-dimensional polymeric chain arrangement in which two of the three copper sites in each triangular 'platform' are formally five-coordinate through binding to a heterocyclic nitrogen atom. Interaction of the multifunctional linker unit hexamethylenetetramine (hmt) with [Cu3(L3)3] afforded an unusual, chiral, three-dimensional molecular framework of stoichiometry [Cu3(L3)3(hmt)]n. The latter incorporates the trinuclear units coordinated to three triply bridging hmt units. In marked contrast to the formation of the above structures incorporating bifunctional linker units and five-coordinate metal centres, the trinuclear platform [Cu3(L2)3] reacts with the stronger difunctional base 1,4-diazabicyclo[2.2.2]-octane (dabco) to yield a highly symmetric trigonal columnar species of type {[Cu3(L4)3(dabco)3] x 3H2O}n in which each copper centre is octahedrally coordinated.  相似文献   

18.
The reaction of 2,6-diformyl-4-methylphenol, ethylenediamine and Cu(Ⅱ) in the proportion of 3:2:2 yields a new tetranuclear copper(Ⅱ) complex, [Cu2L]2(ClO4)2·2H2O (H3L = N,N'-bis(4-(3'-formyl-5'-methylsalicyclidene)iminoethyl)-4-methyl-2,6-bimethyliminophenol). The complex has been characterized by ES-MS, IR and X-ray diffraction analysis, and its crystal crystallizes in the triclinic system, space group P1 with a = 10.8673(11), b = 12.0829(12), c = 14.4834(15) A, α = 111.946(2), β = 105.828(2), γ = 99.583(2)°, V = 1618.5(3) A3, Dc = 1.605 g/cm3, Z = 2, Mr = 1564.26, F(000) = 800.0,μ(MoKa) = 1.460/mm, S = 1.063, R = 0.0612 and wR = 0.1163 for 6245 observed reflections (I > 2σ(Ⅰ)). The complex is a dimer of dinuclear copper(Ⅱ) acylic enantiomorph subunit [Cu2L]CIO4·H2O, held together by π…π, weak coordination and hydrogen bonding interactions. In addition, the π…π interactions related to phenyl moieties as well as CH=N…π interactions were also found to stabilize the supramolecular architectures in the solid state.  相似文献   

19.
The equilibria of copper(II) with (S)-glutamic-gamma-hydroxamic acid (H2L) were investigated in aqueous solution by different techniques: glass electrode potentiometry; calorimetry; VIS and CD spectrophotometry; and ES-MS. An unexpected pentacopper(II) 12-metallacrown-4 [Cu5L4H(-4)](2-) was detected, analogous to those well known formed by alpha- and beta-aminohydroxamic acids, but of lower stability. Another five species were found: [CuLH]+; [CuL2H2]; [Cu2L2]; [CuL2H]-; and [CuL2]2-. Their structures are proposed based on both spectroscopic and calorimetric data.  相似文献   

20.
A Tetraaza Macrocylic Ligand (H2L) and its complexes, [Cd(H2L)(OH2)2](NO3)(2)·1/2OH2 (I), [Co(H2L)(OH2)](NO3)(2)·1/2OH2 (II), [Cu(H2L)(NO3)2]·3/2OH2 (III) and [Ni(H2L)(NO3)(OH2)]NO3·OH2 (IV), have been synthesized and characterized on the basis of elemental analysis, molar conductivity, 1H NMR, UV-vis, FT-IR and mass spectroscopy. All results confirm that the prepared compounds have 1:1 metal-to-ligand stoichiometry, octahedral configuration and the ligand behaves as a neutral tetradendate towards the metal ions. [CdL(OH2)2] (V), [CoL(OH2)2] (VI), [CuL(OH2)2] (VII) and [Ni(H2L)(NO3)2] (VIII) were synthesized pyrolytically in solid state from corresponding compounds (I-IV). Analytical results of complexes (V-VIII) show that the ligand behaves either as a neutral tetradendate or dianionic tetradentate ligand towards the metal ions. The binding of H2L and its copper complex (III) to DNA has been investigated by ultraviolet absorption spectroscopy. The experiments indicate that H2L and its copper complex (III) can bind to DNA through an intercalative mode. The H2L and its copper complex (III) exhibited anti-tumor activity against Ehrlich Acites Carcinoma (E.A.C) at the concentration of 100 μg/ml.  相似文献   

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