Flow based determination of Cr(VI) by adsorptive cathodic stripping voltammetry on an immobilized magnetic poly(ionic liquid) modified electrode.

In this work an electrochemical procedure for Cr(VI) flow based determination in tap water is presented. An AdCSV method was developed using a screen printed electrode modified with magnetic poly(1-allyl-3-methylimidazolium) chloride and the procedure does not require the addition of complexing agents in the solution unlike the methodologies reported so far for Cr(VI) determination. The flow based system is described and the control variables were studied in detail and optimized using a Taguchi parameters design.

Three-way principal component analysis as a tool to evaluate the chemical stability of metal bearing residues from wastewater treatment by the ferrite process.

The chemical fractionation patterns of eight metals (Cd, Co, Cu, Cr, Mn, Ni, Pb and Zn) have been determined in 27 metal-bearing residues by using the BCR sequential extraction procedure. The residues were generated as by-products during the optimization of a semi-continuous reactor for metal removal from wastewater based on ferrite synthesis by co-precipitation. The three-dimensional X dataset (samples×metals×fractions) obtained by applying the BCR procedure has been analyzed by multivariate methods: matrix augmentation (MA-PCA) and three-way principal component analysis, 3-PCA (PARAFAC and Tucker3 models).

Amperometric flow system for blood glucose determination using an immobilized enzyme magnetic reactor.

An amperometric flow system for glucose determination in blood serum samples after enzymatic reaction with glucose oxidase immobilized on magnetite covered with silica gel modified propylamine is described. The solid was magnetically retained on a mini-column and placed into the flow injection system preceding the amperometric detector using a modified screen printed electrode with [Fe(tris(3,5-dimetyl-1-pyrazolyl)borate)(2)](+)[FeCl(4)](-). The variables involved in the system such as flow rate, enzyme concentration, injection volume and reaction coil length were evaluated using a Taguchi parameter design.

Amperometric biosensor for oxalate determination in urine using sequential injection analysis.

An amperometric flow biosensor for oxalate determination in urine samples after enzymatic reaction with oxalate oxidase immobilized on a modified magnetic solid is described. The solid was magnetically retained on the electrode surface of an electrode modified with Fe (III)-tris-(2-thiopyridone) borate placed into a sequential injection system preceding the amperometric detector. The variables involved in the system such as flow rate, aspired volumes (modified magnetic suspension and sample) and reaction coil length were evaluated using a Taguchi parameter design.

Validation of a tubular bismuth film amperometric detector. Determination of diclofenac sodium by multisyringe flow injection analysis.

A tubular bismuth film electrode (BFE), installed as part of a multisyringe flow injection system, was used as an amperometric detector to determine the concentration of diclofenac sodium in pharmaceutical formulations. A tubular voltammetric detection cell was employed, in which the hydrodynamic flow conditions were not disturbed. This automated method allows the continuous regeneration of the BFE, preventing passivation of the detector and improving the sensitivity of detection.