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A simple and selective spectrophotometric flow injection determination of trace amounts of ruthenium by catalytic oxidation of safranin-O 总被引:1,自引:0,他引:1
In this work, a simple, selective and rapid flow injection method has been developed for determination of ruthenium. The method is based on its catalytic effect on the oxidation of safranin-O by metaperiodate. The reaction was monitored spectrophotometrically by measuring safranin-O absorbance at lambdamax=521. The reagents and manifold variables, which have influences on the sensitivity, were investigated and the optimum conditions were established. The optimized conditions made it possible to determine ruthenium in the ranges of 0.4-20.0 ng/mL (DeltaA=0.2819CRu+1.1840) and 20.0-100.0 ng/mL (DeltaA=0.0984CRu+7.9391) with a detection limit of 0.095 ng/mL and a sample rate of 30+/-5 samples/h. Relative standard deviation for the five replicate measurements was less than 1.84%. The proposed method has been successfully applied for analysis of ultra trace amounts of ruthenium in real samples. 相似文献
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Mohsen Keyvanfard Razieh Shakeri Hassan Karimi-Maleh Khadijeh Alizad 《Materials science & engineering. C, Materials for biological applications》2013,33(2):811-816
A carbon-paste electrode modified with multiwall carbon nanotubes (MWCNTs) was used for the sensitive and selective voltammetric determination of ascorbic acid (AA) in the presence of 3,4-dihydroxycinnamic acid (3,4-DHCA) as mediator. The mediated oxidation of AA at the modified electrode was investigated by cyclic voltammetry (CV), chronoamperommetry and electrochemical impedance spectroscopy (EIS). Also, the values of catalytic rate constant (k), and diffusion coefficient (D) for AA were calculated. Using square wave voltammetry (SWV), a highly selective and simultaneous determination of AA, acetaminophen (AC) and tryptophan (Trp) has been explored at the modified electrode. The modified electrode displayed strong function for resolving the overlapping voltammetric responses of AA, AC and Trp into three well-defined voltammetric peaks. In the mixture containing AA, AC and Trp, the three compounds can well separate from each other with potential differences of 200, 330 and 530 mV between AA and AC, AC and Trp and AA and Trp, respectively, which was large enough to determine AA, AC and Trp individually and simultaneously. 相似文献
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A flow injection method is proposed for determining vanadium(V). The method is based on its catalytic effect on the oxidation of malachite green oxalate by bromate. The reaction was monitored spectrophotometrically by measuring malachite green oxalate absorbance at λmax = 625 nm. The reagents and manifold variables, which have influences on the sensitivity, were investigated and the optimum conditions were established. The optimized conditions made it possible to determine vanadium in the ranges of 10-140 ng/mL with a detection limit of 5.2 ng/mL and a sample rate of 20 ± 5 samples/h. 相似文献
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Keyvanfard Farzaneh Shoorehdeli Mahdi Aliyari Teshnehlab Mohammad Nie Ke Su Min-Ying 《Neural computing & applications》2012,21(1):35-44
In the conventional CMAC-based adaptive controller design, a switching compensator is designed to guarantee system stability
in the Lyapunov stability sense but the undesirable chattering phenomenon occurs. This paper proposes a CMAC-based smooth
adaptive neural control (CSANC) system that is composed of a neural controller and a saturation compensator. The neural controller
uses a CMAC neural network to online mimic an ideal controller and the saturation compensator is designed to dispel the approximation
error between the ideal controller and neural controller without any chattering phenomena. The parameter adaptive algorithms
of the CSANC system are derived in the sense of Lyapunov stability, so the system stability can be guaranteed. Finally, the
proposed CSANC system is applied to a Chua’s chaotic circuit and a DC motor driver. Simulation and experimental results show
the CSANC system can achieve a favorable tracking performance. It should be emphasized that the development of the proposed
CSANC system doesn’t need the knowledge of the system dynamics. 相似文献
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