共查询到19条相似文献,搜索用时 234 毫秒
1.
本文研究了利用亚硝基R盐螯合形成的树脂,分离富集试液中痕量贵金属元素铱的实验条件。并利用JP-1型示波极谱仪,在1.50mol/L盐酸+5.0×10^-5mol/L硫脲+0.2mol/L盐酸+5.0×10^-5mol/L硫脲+0.2mol/L碘化钾+碲(ρ(B)=0.4mg/L)的混合底液中,对铱进行极谱催化波测定。在示波极谱仪上峰电位约-0.55V(银汞齐为参比电极),可测定试液中5.0×1.0 相似文献
2.
青藤碱和黄芩甙的极谱特性 总被引:7,自引:0,他引:7
用单扫示小极谱法研究了青藤碱和黄芩甙的电化学行为,青藤碱在0.1mol/L Na2B4O7中有两个还原峰,峰P1和P2的电位分别为-1.45V和-1.67V,峰P1的峰电流与浓度在0.06-1.8mg/L和2.0-34.6mg/L范围内呈线性关系,检测限为0.02mg/L,在0.05mol/L棕檬酸钠+0.2mol/L HCl底液中,黄芩甙于-1.14V(P30和-1.32V(P4)处产生两还原峰 相似文献
3.
乙基橙指示催化动力学极谱法测定痕量铜 总被引:3,自引:0,他引:3
1 引 言在HAc-NaAc介质中,邻菲■啉(phen)存在下,痕量铜对抗坏血酸还原乙基橙反应具有强烈的催化作用,且在此条件下乙基橙于-0.30V(νs SCE)处,有一灵敏的极谱波,以此作为监测反应过程中乙基橙的浓度变化,建立了测定铜的催化动力学极谱方法。2 实验部分2.1 仪器与试剂 JP3-1型示波极谱仪(山东电讯七厂),CS501型超级恒温器(重庆试验设备厂)。0.50mg/LCU(Ⅱ)标准溶液;7.0x10-4mol/L乙基橙溶液;0.5mol/L HAc-NaAC缓冲溶液(pH=4.… 相似文献
4.
单扫描极谱法测定水中痕量苯酚 总被引:12,自引:2,他引:10
苯酚与对硝基苯胺的重氮盐偶合后,在0.03mol/L Na2CO3-0.03mol/L NaHCO3-160g/L乙醇介质中,偶合产物在单扫描示波极谱上产生一个灵敏而精晰的吸附还源波,波高与苯酚浓度在0.005~0.5mg/L范围内呈良好线性关系,峰电位为-.058V(υs,SCE),方法检出限达0.002mg/L。已用于天然水中痕量苯酚的测定。 相似文献
5.
柚皮革甙的电化学研究 总被引:1,自引:0,他引:1
用单扫示波极谱法,柚皮甙在0.1mol/LKH2PO4中(PH=4.60)有一灵敏的二阶 导数峰,峰电位为-1.43C,峰电流与浓度在0.1-2.8mg/L和3.0-42mg/L范围良好线性关系, 相似文献
6.
测定超氧化物歧化酶活性的一种新的极谱分析方法 总被引:3,自引:0,他引:3
报道一种测定超氧化物歧化酶活生的新极谱分析方法,在0.125mol/LNH3.H2O-0.75MOL/l nh4cL-2.5%,Na2SO3-0.5%,吐温-80-的介质中,SOD在-0.52V处产生一氧极谱催化波。SOD在1.0×10^3U/L-4.0×10^3U/L的活性含量范围内与催化电流呈线性关系,检出限为8.0×10^2U/L。 相似文献
7.
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
8.
9.
示波极谱法测定内燃机车冷却液中亚硝酸根含量 总被引:5,自引:0,他引:5
采用JP3-1型示波极谱仪,滴东电极1.5次微分,在-0.6~-1.90V范围内,通过对多种底液组分的试验,确定了在2.00×10^-3mol.L^-1Mn^2+,盐酸(pH2)底液中,NO^-2在-1.32V(vs.SCE)处于生极谱法,NO2浓度在4.00×10^-5~4.00×10^-3mol.L^-1范围与峰高呈线性关系。方法可用于测定内燃机车冷却液中NO2含量,其选择性好,操作简便,快速 相似文献
10.
在0.004mol/L HCl-1×10^-3mol/L SCN^--5×10^-5mol/L磷酸三丁酯(TBP)溶液中,Cu^2+可在-0.42V(vs.SCE)产生灵敏的极谱波,波高较无TBP存在时增加近3倍,二阶导数峰电流与0.005 ̄4.0mg/L Cu^2+呈线性关系。研究了极谱波性质及增敏机理,表明该极谱波为配合物吸附波,TBP起协同吸附作用。本法已用于实际样品分析,结果满意。 相似文献
11.
采用4%的乙酸浸泡陶瓷样品24 h,应用同位镀汞差分脉冲溶出伏安法测定了陶瓷样品中微量重金属铅、镉的溶出量。以0.1 mol/L的硝酸溶液做底液,0.1 mol/L的KCl溶液做支持电解质,2 g/L的Hg2+溶液做镀汞液,测得铅的溶出峰电位为-0.5 V(vsSCE),镉的溶出峰电位为-0.7 V(vsSCE),两者含量在5×10-4~1 mg/L和5×10-4~0.5 mg/L范围内峰电流和其含量呈良好的线性关系,检出限分别为2×10-4和4.3×10-3mg/L。 相似文献
12.
Newton L Dias Filho Devaney R do Carmo Laércio Caetano André H Rosa 《Analytical sciences》2005,21(11):1359-1363
A mercury-sensitive chemically modified graphite paste electrode was constructed by incorporating modified silica gel into a conventional graphite paste electrode. The functional group attached to the (3-chloropropyl) silica gel surface was 2-mercaptoimidazole, giving a new product denoted by 3-(2-thioimidazolyl)propyl silica gel, which is able to complex mercury ions. Mercury was chemically adsorbed on the modified graphite paste electrode containing 3-(2-thioimidazolyl)propyl silica (TIPSG GPE) by immersion in a Hg(II) solution, and the resultant surface was characterized by cyclic and differential pulse anodic stripping voltammetry. One cathodic peak at 0.1 V and other anodic peak at 0.34 V were observed on scanning the potential from -0.1 to 0.8 V (0.01 M KNO3; v = 2.0 mV s(-1) vs. Ag/AgCl). The anodic peak at 0.34 V show an excellent sensitivity for Hg(II) ions in the presence of several foreign ions. A calibration graph covering the concentration range from 0.02 to 2 mg L(-1) was obtained. The detection limit was estimated to be 5 microg L(-1). The precision for six determinations of 0.05 and 0.26 mg L(-1) Hg(II) was 3.0 and 2.5% (relative standard deviation), respectively. The method can be used to determine the concentration of mercury(II) in natural waters contaminated by this metal. 相似文献
13.
在NaOH(pH 10.0)介质中,美托拉腙分别在-1.810 V和-2.075 V处具有2个还原峰,DNA的加入导致美托拉腙的2个还原峰峰电位正移,峰电流下降,表明美托拉腙与DNA之间发生了相互作用,形成了非电活性的化合物.考察了时间、温度、扫描速率、离子强度等条件对该相互作用的影响;结合DNA对美托拉腙紫外吸收光谱的影响,推断美托拉腙分子与DNA分子的相互作用是通过嵌插方式结合.在优化条件下,反应体系在-2.075 V处的还原峰电流I_(pa)与DNA的质量浓度在6 ~36 mg/L范围内呈较好的线性关系,相关系数为0.994 8,检出限为3 mg/L;通过对反应机制的研究,得到美托拉腙与DNA间的结合常数β为1.334×10~4 L/mol,结合数为2. 相似文献
14.
A simple, rapid, and accurate method for the separation and determination of physcion, chrysophanol, aloe-emodin, and emodin in Rhubarb, Juemingzi, and Chinese herbal preparations was developed by combination of flow injection-capillary zone electrophoresis for the first time. The analysis was carried out using an unmodified fused-silica capillary (75 mm x 50 microm ID x 375 microm OD, effective separation length of 48 mm) and direct ultraviolet detection at 254 nm. By a series of optimization, the sample solvent consisted of NaOH (100 mmol/L) and ACN (1:1 v/v), and a running buffer composed of 15 mmol/L sodium borate - 12.5 mmol/L sodium dihydrogen phosphate - 42% v/v ACN (pH 10.1) was applied for the separation of the four anthraquinones. The separation was rapid and highly reproducible, with complete resolution of all four compounds within 6 min. The sample throughput rate could reach up to 12 per h. The repeatability (defined as relative standard deviation) was 4.45, 4.44, 4.34, 0.61% with peak height evaluation and 1.62, 0.89, 2.49, 2.19% with peak area evaluation for physcion, chrysophanol, aloe-emodin, and emodin, respectively. 相似文献
15.
液相色谱/蒸发光散射测定转基因烟草提取液中的海藻糖 总被引:6,自引:0,他引:6
采用乙二胺动态修饰硅胶柱分离、蒸发光散射检测器测定了转基因烟草提取液中的糖。 4种糖的峰面积标准曲线在 10 0mg/L~ 15 0 0mg/L范围内均具有良好的线性关系。所建立的方法对果糖、葡萄糖、蔗糖、海藻糖的检测下限分别为 10mg/L ,2 0mg/L ,10mg/L和 10mg/L。 相似文献
16.
抗癌药物博莱霉素伏安行为及其反应机理研究 总被引:12,自引:1,他引:12
博莱霉素(BLEO)A5在0.05mol/L H2SO4溶液中出现两个还原波,峰电位分别为EP1=-0.83V和EP2=-1.09V(vs.,Ag/AgCl)。用线性扫描与循环伏安法、恒电位库仑法、脉冲极谱、交流极谱等手段研究体系的伏安行为及反应机理。实验表明,P1为BLEOA5分子中嘧啶环第一步两电子还原的吸附波,P2为嘧啶环第二、三步还原和催化氢还原的具有吸附性的重叠波。 相似文献
17.
Study on the adsorptive catalytic voltammetry of aloe-emodin at a carbon paste electrode 总被引:1,自引:0,他引:1
LI Ju’nan GAO Peng LI Xiangling YAN Zhihong & MAO Xun College of Chemistry Xiangtan University Xiangtan China 《中国科学B辑(英文版)》2005,48(5):442-448
Recently, the studies and applications for the pola-rographic catalytic waves of organic compounds at dropping mercury electrode made considerable head-way. Tovopova et al.[1―4] reported the polarographic catalytic waves of the organic compounds containi… 相似文献
18.
A capillary electrophoretic assay for determining aloe-emodin (AE), methyl p-coumarate (MC), and 3,4-dihydro-6,8-dihydroxyl-[(3s)-2'-acetyl-3'-hydroxyl-5'-methoxy-benzyl]-isocoumarin (DDI) in Aloe vera has been developed. Baseline separation was achieved within 15 min using a running buffer of 20 mm borax containing 10% (v/v) acetonitrile at pH 10.5. A linear relationship between the peak area and the concentration of the analytes was found in the ranges 5-500, 10-1000 and 2-1000 micro g/mL for AE, MC and DDI, respectively, with correlation coefficients of 0.9992-0.9998. The relative standard deviations of migration time and peak area were within 0.17-0.19 and 1.52-3.37%, respectively. The recoveries of AE, MC and DDI were 105, 102 and 96.4%. The contents of AE, MC and DDI in Aloe vera were measured to be 5.13, 0.768 and 1.30 mg/g, respectively. 相似文献
19.
依沙吖啶在玻碳电极上的阳极伏安行为 总被引:4,自引:0,他引:4
用直流伏安法(DCV)、微分脉冲伏安法(DPV)和循环伏安法(CV)在玻璃电极(GCE)上研究了依沙吖啶(EAD)在不同介质中的阳极伏安行为,发现在0.1mol/L氢氧化钠溶液中于0.38V(vs.Ag/AgCl)左右产生一个良好的阳极氧化峰,浓度在0.05-80mg/L之间与其峰电流呈线性关系,用本法不需要分离,可直接测定药物制剂和加标尿样,RSD为1.4%-2.7%(n=10)。尿样中EAD的回收率为89%-95%。探讨了EAD在GEC上的电极反应机理。 相似文献