Development of persulfate-based advanced oxidation processes to remove synthetic azo dyes from aqueous matrices.

Azo dyes are largely used in many industries and discharged in large volumes of their effluents into the aquatic environment giving rise to non-esthetic pollution and health-risk problems. Due to the high stability of azo dyes in ambient conditions, they cannot be abated in conventional wastewater treatment plants. Over the last fifteen years, the decontamination of dyeing effluents by persulfate (PS)-based advanced oxidation processes (AOPs) has received a great attention.

Mineralization of desmetryne by electrochemical advanced oxidation processes using a boron-doped diamond anode and an oxygen-diffusion cathode.

The mineralization of acidic aqueous solutions of the herbicide desmetryne has been studied by electrochemical advanced oxidation processes (EAOPs) such as anodic oxidation with electrogenerated H(2)O(2) (AO-H(2)O(2)), electro-Fenton (EF) and photoelectro-Fenton (PEF) with UVA light. Electrolyses were conducted in an open and cylindrical cell with a boron-doped diamond (BDD) anode and an O(2)-diffusion cathode for H(2)O(2) generation. The main oxidizing species are ()OH radicals formed at the BDD surface in all treatments and in the bulk from Fenton's reaction between added Fe(2+) and electrogenerated H(2)O(2) in EF and PEF.

Determination of polyphenols in wines by liquid chromatography with UV spectrophotometric detection.

This paper describes a new chromatographic method for the determination of polyphenolic compounds in wines. The method is based on the separation of analytes by reversed-phase mode in a C18 column (2.6 μm particle size) and UV absorption spectroscopy.

Degradation of atrazine by electrochemical advanced oxidation processes using a boron-doped diamond anode.

Solutions of 30 mg L(-1) of the herbicide atrazine have been degraded by environmentally friendly electrochemical advanced oxidation processes (EAOPs) such as anodic oxidation (AO), electro-Fenton (EF), and photoelectro-Fenton (PEF) using a small open and cylindrical cell with a boron-doped diamond (BDD) anode. AO has been carried out either with a stainless steel cathode or an O(2) diffusion cathode able to generate H(2)O(2). Hydroxyl radicals ((*)OH) formed at the BDD surface in all EAOPs and in the bulk from Fenton's reaction between added Fe(2+) and electrogenerated H(2)O(2) in EF and PEF are the main oxidants.

Determination of HIV drugs in biological matrices: a review.

The present paper reviews the recent advances on the determination of antiretroviral drugs against the human immunodeficiency virus (HIV). Methods have been reviewed with special emphasis on the principal analytical strategies for dealing with clinical samples as well as the determination of the newest drugs. The most critical steps of the analytical procedures including the sample treatment, separation and validation have been discussed.

Cellular adhesion, proliferation and viability on conducting polymer substrates.

This work reports a comprehensive study about cell adhesion and proliferation on the surface of different electroactive substrates formed by pi-conjugated polymers. Biological assays were performed considering four different cellular lines: two epithelial and two fibroblasts. On the other hand, the electroactivity of the three conducting systems was determined in physiological conditions.

Reversed-phase liquid chromatographic method with spectrophotometric detection for the determination of antiretroviral drugs.

In the present paper, a new chromatographic method for the determination of acquired immune deficiency syndrome (AIDS) drugs in plasma samples is proposed. The method consists of solid-phase extraction for sample pretreatment and further chromatographic analysis. Drugs have been separated on a C(18) column using an elution gradient based on an increase in the acetonitrile percentage.

Flow-injection spectrophotometric determination of reverse transcriptase inhibitors used for acquired immuno deficiency syndrome (AIDS) treatment: focus on strategies for dealing with the background components.

This paper describes a rapid method for the quantification of reverse transcriptase inhibitors in mixtures of therapeutic interest containing zidovudine, zalcitabine and nevirapine. The method is based on a pH-gradient flow-injection system with diode array detection and further data analysis using multivariate curve resolution. Data matrices of unknown samples mixtures have been analyzed simultaneously with those of standards and background via the construction of augmented data matrices.

Flow-injection determination of zidovudine in plasma samples using multivariate curve resolution.

This paper describes a spectrophotometric flow-injection method for the determination of an antiretroviral drug (zidovudine) in plasma samples. The main goal of this study is the development of feasible analytical method to monitor the plasmatic drug levels in a rapid and simple way as an alternative to chromatographic procedures. The flow-injection system proposed consists of a two-channel manifold with the injection of the sample into an acid carrier and on-line generation of a pH-gradient.

Excitation and damping of disturbances in cylindrical coronal loops.

The excitation and damping of transversal coronal loop oscillations is studied using one-and two-dimensional models of line-tied cylindrical loops. By solving the time-dependent magnetohydrodynamic equations it is shown how an initial disturbance generated in the solar corona induces kink mode oscillations. We investigate the effect of the disturbance on a loop with a non-uniform boundary layer.