The paper proposes a simple and sensitive approach for the preconcentration and determination of graphene oxide (GO) in environmental samples by using fluorescent graphene quantum dots (GQDs). The method is based on the preconcentration of GO on a cellulose membrane and their subsequent elution prior to fluorescence analysis of the quenching effect produced on the GQD solution due to the hydrop...

a new method for the separation and preconcentration of trace amounts of cadmium in food and water samples by magnetic solid phase extraction (mspe) with fe3o4 magnetic nanoparticles (fe3o4-mnps) and its determination by flame atomic absorption spectrometry has been developed. for this purpose, fe3o4-mnps were synthesized via chemical precipitation method. the extraction of cadmium ions from th...

A system for on-line preconcentration and determination of lead by flame atomic absorption spectrometry (FAAS) was proposed. It was based on the sorption of lead(II) ions on a minicolumn of polyurethane foam loaded with 2-(2-thiazolylazo)-5-dimethylaminophenol (TAM). The optimisation step was carried out using two-level full factorial and Doehlert designs for the determination of the optimum co...

A novel, simple method has been developed for the preconcentration of Cu(II) based on the adsorption of its Schiff’s cupferron complex on a multi walled carbon nanotubes (MWCNTs) onto C18 cartridge .A new technique using a solid phase extraction (SPE) cartridge with modified Schiff’s Cupferron complex on a multi walled carbon nanotubes (MWCNTs) onto C18 cartridge as sorbent was developed for th...

absorption spectrometry was developed. The performance of retain transition metal ions. After the sample loading step, the the on-line preconcentration system was tested by determining metal ions are stripped from the column with a suitable eluent Cu and Mo in sea-water. Calibration graphs constructed from and directly injected into the nebulizer of a flame atomic the preconcentration of standa...

We present the first sensing system for metal ions based on the combination of separation/preconcentration by a permeation liquid membrane (PLM) and fluorescence detection with an optical fiber. As a model, a system for the detection of Cu(II) ions was developed. The wall of a polypropylene hollow fiber serves as support for the permeable liquid membrane. The lumen of the fiber contains the str...

A sensor, based on multi-wall carbon nanotubes modified glassy carbon electrode (MWCNT/GCE), was developed for determination of fenitrothion. Determining the surface area of MWCNT/GCE showed that this surface is three times more active than that of a glassy carbon electrode. The experimental parameters, such as the amount of MWCNTs, pH of the fenitrothion solution, preconcentration potential an...

A simple and highly sensitive separation and preconcentration procedure, which has minimal impact on the environment, has been developed. The procedure is based on the carrier element free coprecipitation (CEFC) of Co(II), Cu(II), and Ni(II) ions by using 2-{4-[2-(1H-indol-3-yl)ethyl]-3-(4-methylbenzyl)-5-oxo-4,5-dihydro- 1H-1,2,4-triazol-l-yl}-N'-(pyridin-2-yl methylidene)acetohydrazide (IMOTP...

A method for separation and preconcentration of Cu(II), Ni(II), Cd(II) using N-N'-bis(5-methoxsalicylidene)-2-hydroxy-1,3-propanediamine modified silica gel was improved aqueous samples pharmaceuticals. Determination the analytes achieved by inductively coupled plasma optic emission spectrometry. The experimental conditions including pH value, sample volume, eluent type sorbent mass, sample, fl...

a highly selective, sensitive, rapid and economical differential pulse polarographic method has been developed for the determination of trace amounts of antimony in various standard alloys and biological samples after adsorption of its 2-nitroso-1-naphthol-4-sulfonic acid - tetradecyldimethylbenzylammonium chloride on microcrystalline naphthalene in the ph range of 7.5-11.0. after filtration, t...