The zalcitabine (ddC) has been extensively used in the treatment of HIV patients due to its antiretroviral activity. The quality control of this active principle in medications is of outstanding importance to public health. The principal objective of the current study was the development of an alternative analytical methodology for the zalcitabine determination using a voltammetric process. The...

A flow injection square wave cathodic stripping voltammetric method has been developed for the determination of sertraline in a pharmaceutical preparation. The method shows linearity between peak current intensity and sertraline concentration for the interval between 0.20 x 10(-6) and 1.20 x 10(-6) mol L(-1). Limits of detection and quantification were found to be 1.5 x 10(-7) and 5.0 x 10 (-7)...

The mechanical activation (polishing) of screen-printed electrodes (SPEs) is explored and shown to exhibit an improved voltammetric response (in specific cases) when polished with either commonly available alumina slurry or diamond spray. Proof-of-concept is demonstrated for the electrochemical sensing of nitrite where an increase in the voltammetric current is found using both polishing protoc...

Sulfur speciation was determined in real time in salt marsh microbial mats, subtidal sediments and hydrothermal vent diffuse flow waters using solid state gold-amalgam voltammetric microelectrodes. Chemical species were measured in situ without any sample manipulation or processing. The partially oxidized sulfur species detected were polysulfides, thiosulfate, elemental sulfur and tetrathionate...

There is a continuous need for the construction of detection systems in microfluidic devices. In particular, electrochemical detection allows the separation of signals from the analyte and interfering substances in the potential domain. Here, a simple microfluidic device for the sensitive and selective determination of dopamine in the presence of interfering substances was constructed and teste...

The electrochemical behavior of 2'-halogeno-N,N-dimethyl-4-aminoazobenzene derivatives was investigated using various polarographic and voltammetric methods. The peak potentials of these derivatives were observed to shift towards negative values along with an increase in the pH. A reduction of the azo linkage took place via two electrons at pH > 4, but four electrons at pH < 4 in aqueous-ethano...

Single-walled carbon nanotubes (SWNTs) were effectively dispersed and functionalized by wrapping with single-stranded DNA (ssDNA). The ssDNA-SWNTs attach strongly on glass substrate and easily form a uniform film, making it possible for electrochemical analysis and sensing. The film was fabricated into a working electrode, which exhibited good electrochemical voltammetric properties, such as fl...

Carbon paste electrode modified with cobalt impregnated zeolite was prepared by mixing of cobalt_zeolite (Co_Z) and graphite powder with different percent. The electrochemical oxidation of cefixime at such electrodes was investigated using the cyclic voltammetric and amperometric techniques. It is not electrochemically active towards cefixime oxidation in 0.1 M phosphate buffer solution (pH=7) ...

The application of voltammetric methods using different rates of polarisation on HMDE reveal inert or labile behaviour of Cd- or Zn- complexes in the presence of excessive cadmium or zinc ions in solution. This phenomenon was demonstrated first on the simplest phytochelatin - complex of peptide (gamma-Glu-Cys)(2) Gly with cadmium, later on rabbit liver metallothioneins - Cd(7) MT in the presenc...

conclusions the results of this study show that lh in different pharmaceutical preparations could be determined with good reliability. in addition, the results reveal that the equal numbers of electrons and protons are involved in the oxidation of lh and the irreversible oxidation of an analyte was performed via amine groups of lh molecule. background lidocaine hydrochloride (lh) is one of the ...