Tetrakis(4-carboxyphenyl)porphyrin (TCPP) has been loaded on aminopropyl-silica gel by physical adsorption and by direct immobilization through formation of an amide bond to obtain chelating sorbents. These sorbents have been studied for preconcentration and separation of vanadium prior to its determination by atomic absorption spectrometry. Several parameters, such as sorption capacity of the ...

In this study, a new type of alumina-coated magnetite nanoparticles (Fe3O4/Al2O3 NPs) with sodium dodecyl sulfate1-(2-pyridylazo)-2-naphthol (SDS-PAN) as a new sorbent solid phase extraction (SPE) has been successfully synthesized and applied for preconcentration and separation of Pb (II). The metal was eluted with 3 mL HNO3 2 mol L directly and detected by flame atomic absorption spectrometry ...

A numerical study on the influence of electroosmotic flow on analyte preconcentration by isotachophoresis ( ITP) is made. We consider that the double layer induced electroosmotic flow ( EOF) counterbalance the electrophoretic velocity and a stationary ITP stacked zones results. We solve the Navier-Stokes equations coupled with the Nernst-Planck equations to determine the local convective veloci...

A fully automated procedure for the determination of rhodium has been developed using flow injection (FI) on-line microcolumn preconcentration coupled with electrothermal atomic absorption spectrometry (ETAAS). The proposed FI manifold and its operation make possible the introduction of the total eluate volume into the graphite atomizer, avoiding the necessity for optimisation of subsampling th...

Spiny-like spherical copper metal–organic frameworks (SSC-MOFs) were prepared and characterized via SEM, TEM, EDS, XRD, FTIR the BET surface area. The fabricated SSC-MOFs applied to develop a procedure for microextraction of trace arsenic(III) preconcentration. results show that copper- imidazole-derived framework was formed in sphere with spiny area 120.7 m2/g. TEM confirmed perforated network...

A preconcentration/separation procedure is presented for the solid phase extractionof trace cadmium and lead ions as their 2-propylpiperidine-1-carbodithioate (PPCD) chelates inenvironmental samples on Nano Graphene, prior to cadmium and lead determinations by atomicabsorption spectrometry. The preconcentration procedure was optimized by using model solutionscontaining c...

The anodic stripping voltammetric determination of gold was accomplished on a chemically modified glassy carbon electrode in a solution containing chloride ions. A modifying polymer, polyvinylferrocene, was coated by immersing the glassy carbon surface in its solution in methylene chloride followed by solvent evaporation. Tetrahalo complexes of gold, tetrachloroaurate(III) and tetrabromoaurate(...

A method for the preconcentration of Cu, Fe, Pb, Ni, Cd and Bi as their diethyldithiocarbamate chelates was proposed using a column filled with Amberlite XAD-4 resin. The retained analytes on the resin were recovered with a small volume of acetone. The metal ions in the effluent were determined by a flame atomic absorption spectrometer. Different factors including pH of sample solution, sample ...

A disposable copper (II) ion biosensor based on self-assembly of L-cysteine on gold nanoparticle-modified screen-printed carbon electrode was fabricated. The electrode was modified by attaching gold nanoparticles onto the surface of screen-printed carbon electrode through seed mediated growth method followed by self-assembly of L-cysteine. As demonstrated by differential pulse voltammetry, the ...

A simple, sensitive, reliable and flexible flow injection spectrophotometric method is proposed for on-line preconcentration and determination of trace amounts of zinc in water. At the presence of Tween-80 in pH 9.3 buffer solutions, the shade of color of Zn (II)-PAN complex is in a linear relation to the zinc amount at the point of the maximum absorption peak of 560 nm. The optimal experimenta...