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11.
安力农的极谱测定及其电化学行为 总被引:4,自引:0,他引:4
在pH5.6,0.15mol/L磷酸盐缓冲溶液(PBS)中,得到了安力农的灵敏极谱吸附波,波的二阶导波高在2×10^-8~8×10^-6mol/L范围内与安力农的浓度成直线关系,检测下限为1×10^-8mol/L,测定出电极过程的电子传递系数a=0.43,表面电极反尖速率常数ks=3.3s^-1,安力农在汞电极上的吸附遵从Langmuir等温式,测得其吸附系数β=8.1×10^5。 相似文献
12.
《Electroanalysis》2006,18(6):573-578
The electroanalytical detection of trace mercury(II) at gold ultra‐microelectrode arrays is reported. The arrays consist of 256 gold microelectrodes of 5 μm in diameter in cubic arrangements which are separated from their nearest neighbor by 100 μm. The array was utilized in nitric acid using linear sweep voltammetry where a linear response from mercury additions over the range 10 μg L?1?200 μg L?1 (10?8?10?6 M) was observed with a sensitivity and detection limit of 0.11 nC/μg L?1 and 3.2 μg L?1 (16 nM) respectively from using a deposition time of 30 s at ?0.2 V (vs. SCE). This methodology was explored in 0.1 and 1 M chloride media over the mercury range 10 μg L?1?200 μg L?1 (5×10?8?10?6 M) where similar sensitivities of 0.087 nC/μg L?1 and 0.078 nC/μg L?1 were observed with an identical detection limit. The protocol is demonstrated to be useful for the determination of mercury for analysis of environmental water samples. 相似文献
13.
Electrochemical studies of famotidine were carried out using voltammetric techniques: cyclic voltammetry, linear sweep and square wave adsorptive stripping voltammetry. The dependence of the current on pH, buffer concentration, nature of the buffer, and scan rate was investigated. The best results for the determination of famotidine were obtained in MOPS buffer solution at pH 6.7. This electroanalytical procedure enabled to determine famotidine in the concentration range 1 × 10−9–4 × 10−8 mol L−1 by linear sweep adsorptive stripping voltammetry (LS AdSV) and 5 × 10−10–6 × 10−8 mol L−1 by square wave adsorptive stripping voltammetry (SW AdSV). Repeatability, precision and accuracy of the developed methods were checked. The detection and quantification limits were found to be 1.8 × 10−10 and 6.2 × 10−10 mol L−1 for LS AdSV and 4.9 × 10−11 and 1.6 × 10−10 mol L−1 for SW AdSV, respectively. The method was applied for the determination of famotidine in urine. 相似文献
14.
单扫描示波极谱法测定扑热息痛 总被引:2,自引:0,他引:2
扑热息痛与NaNO2在中性介质中发生反应,其亚硝化衍生物具有良好的电活性。在pH9.37的Britton-Robinson缓冲溶液中,于-0.56V(vs.SCE)产生灵敏的极谱还原峰,峰电流与扑热息痛质量浓度在0.007-0.4mg/L范围有良好的线性关系,检测下限为5μg/L。此法已用于测定小儿速效感冒灵。 相似文献
15.
在含有 0 .1 0 mol/L KCl,p H=1 0 .2的 NH3- NH4 Cl缓冲溶液中 ,用线性扫描示波极谱法测得 Gd( ) - Cal- red络合物有一灵敏的导数波 ,峰电位在 - 0 .84V,峰电流与钆 ( )的浓度在 1 .0× 1 0 - 7~ 5 .0× 1 0 - 6 mol/L范围内呈线性关系 ,检出限达1 .0× 1 0 - 7mol/L ;另外 ,试剂本身在 - 0 .61 V有导数极谱波 ,该波的峰电流随钆( )的浓度增加而降低 ,也具有一定的线性关系 相似文献
16.
We describe the ultrasonic assisted preparation of barium stannate-graphitic carbon nitride nanocomposite (BSO-gCN) by a simple method and its application in electrochemical detection of 4-nitrophenol via electro-oxidation. A bath type ultrasonic cleaner with ultrasonic power and ultrasonic frequency of 100 W and 50 Hz, respectively, was used for the synthesis of BSO-gCN nanocomposite material. The prepared BSO-gCN nanocomposite was characterized by employing several spectroscopic and microscopic techniques such as X-ray diffraction, X-ray photoelectron spectroscopy, fourier transform infra-red, field emission scanning electron microscopy, and high resolution transmission electron microscopy, to unravel the structural and electronic features of the prepared nanocomposite. The BSO-gCN was drop-casted on a pre-treated glassy carbon electrode (GCE), and their sensor electrode was utilized for electrochemical sensing of 4-nitrophenol (4-NP). The BSO-gCN modified GCE exhibited better electrochemical sensing behavior than the bare GCE and other investigated electrodes. The electroanalytical parameters such as charge transfer coefficient (α = 0.5), the rate constant for electron transfer (ks = 1.16 s−1) and number of electron transferred were calculated. Linear sweep voltammetry (LSV) exhibited increase in peak current linearly with 4-NP concentration in the range between 1.6 and 50 μM. The lowest detection limit (LoD) was calculated to be 1 μM and sensitivity of 0.81 μA μM−1 cm−2. A 100-fold excess of various ions, such as Ca2+, Na+, K+, Cl−, I−, CO32−, NO3, NH4+ and SO42− did not able to interfere with the determination of 4-NP and high sensitivity for detecting 4-NP in real samples was achieved. This newly developed BSO-gCN could be a potential candidate for electrochemical sensor applications. 相似文献
17.
《Analytical letters》2012,45(12):1031-1040
Abstract Linear sweep voltammetry at glassy carbon or other carbon materials is shown to be a simple, highly sensitive, and relatively versatile analytical method for the determination of thiourea and thiourea dioxide. Using the first one-electron oxidation peak occurring at ~0.6V, thiourea can be determined directly in a variety of electrolytes from concentrated acids to solutions of pH ~5. The thiourea dioxide determination is based on the two-electron oxidation peak which appears in a number of electrolytes at ~1.2V. 相似文献
18.
19.
Efficient cross polarization with simultaneous adiabatic frequency sweep on the source and target channels 总被引:2,自引:2,他引:0
In this work, we propose a new and efficient heteronuclear cross polarization scheme, in which adiabatic frequency sweeps from far off-resonance toward on-resonance are applied simultaneously on both the source and target spins. This technique, which we call as Simultaneous ADIabatic Spin-locking Cross Polarization (SADIS CP), is capable of efficiently locking both the source and target spins with moderate power even in the presence of large spectral distribution and fast relaxation. It is shown that by keeping the time-dependent Hartmann-Hahn mismatch minimal throughout the mixing period, polarization transfer can be accelerated. Experiments are demonstrated in a powder sample of L-alanine. 相似文献
20.