magnesium is extracted with a chloroform solution of n-p-tolyl-2- thenohydroxamic acid (pttha) from aqueous solution of ph 9.5 .mg-pttha complex is colourless and the colour is developed by adding quinalizarin into the extract. lmax and e of the complex are 590nm and 2.8´103 lmol -1cm-1respectively.most common  ions do not interfere in the determination of magnesium. the spectral characteristic...

the aim of this work was to develop a selective cloud point extraction method for the separation and preconcentration of copper(ii) prior to spectrophotometric determination. for this purpose dithizone was used as a complexing agent and the experimental solution was acidified with sulfuric acid. triton x-114 was used as a surfactant and after phase separation, based on the cloud point of the mi...

in this work, we developed a simple and selective method for separation and spectrophotometric determination of trace amounts of cetylpyridinium chloride (cpc) in pharmaceutical products using cloud point extraction (cpe) technique. the method is based on cloud point extraction of the cpc in alkali conditions using of nonionic surfactant triton x-114. under selected conditions, the calibration ...

recently, 6-(2-naphthyl)-2, 3-dihydro-as-triazine-3-thione (ndtt) was synthesized in laboratory and used successfully for the spectrophotometric determination of nanogram levels of cu2+ in aqueous solution. this reagent forms a specific red complex with cu2+ ions after the extraction by chloroform at alkaline ph. the absorption of the complex in the uv region (313 nm) is about 8 times as strong...

The direct chelation-extraction method, originally developed by Hessel (1968) for blood lead analysis, has been successfully applied to urinalysis for manganese. The analyses of 35 urine samples containing up to 100 microgram/1 of manganese from manganese-exposed workers showed that the data obtained by this method agree well with those by wet digestion-flame atomic absorption spectrophotometry...

a simple, rapid and sensitive solvent assisted-dispersive solid phase extraction method was developed for the extraction of iron(ii) prior to its spectrophotometric determination. the fe(ii) reacted with 2,4,6-tris(2-pyridyl)-1,3,5-triazine, neutralized with sodium dodecyl sulfate and extracted onto the fine particles of benzophenone which were formed upon rapid injection of a mixture of benzop...

In this research, a Dispersive Liquid-Liquid MicroExtraction (DLLME) method coupled to UV-vis spectrophotometry was developed for the indirect determination of silver ion. The method is based on the catalytic effect of the silver ion on the oxidation of congo red by potassium peroxodisulphate and extraction with DLLME procedure using chloroform (extraction solvent) containing cetyltrimethyl...

The total flavonoids of Houttuynia cordata are determined by UV-Vis spectrophotometry. The extraction condition of flavonoids from Houttuynia cordata includes: the extraction temperature is 70 ̊C, solid-liquid ratio is 1:20, solvent is 80% ethanol, extraction time is 65 min. We studied the antioxidation of flavonoids in Houttuynia cordata, and results showed that flavonoids had strong reducing c...

We present an improved method for ultraviolet spectrophotometry of theophylline in serum. We studied various extraction techniques aimed at eliminating interferences from co-extractable serum constituents. In the resulting modified procedure, 1 ml of serum is required and a salt-solvent pair of ammonium sulfate and chloroform/hexane is used for extraction. The solvent forms the top phase after ...