The solvent extraction of trivalent lanthanoids (La, Nd, Eu, Ho, and Lu) with mixtures of the chelating extractant 1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedione (thenoyltrifluoro-acetone, HTTA) or 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-on (HP) and 4-(2-pyridylazo)-resorcin (PAR, S) in CHCl3 was studied. It was found that in the presence of 4-(2-pyridylazo)-resorcin the lanthanoids were extra...

Nicotinic acid (also known as pyridine-3-carboxylic acid) is widely used in food, pharmaceutical and biochemical industries. The extraction of nicotinic acid by tri-noctylphosphine oxide (TOPO) with kerosene (diluent) is studied. The equilibrium experiments are carried out to investigate the effects of diluent, extractant (TOPO) composition and initial acid concentration on extraction efficienc...

An integrated process coupling solid-liquid extraction and liquid-membrane preconcentration of vincamine was studied. The effect of the ratios solid phase/extractant volume and extractant volume/liquid membrane volume on the mass transfer rate and efficiency of vincamine removal were estimated. It was found that the transfer rate and removal efficiency of the alkaloid were higher with smaller q...

Different extraction conditions were applied to investigate the effect of temperature, extraction time and substrate-extractant ratio on pectin extraction from cocoa husks. Pectin was extracted from cocoa husks using water, citric acid at pH 2.5 or 4.0, or hydrochloric acid at pH 2.5 or 4.0. Temperature, extraction time and substrate-extractant ratio affected the yields, uronic acid contents, d...

A method is proposed for the solvent extraction of cadmium using 1,5-bis(di-2-pyridylmethylene)thiocarbohydrazide (DPTH) as extractant. The optimum extraction conditions were evaluated from a critical study of the effect of pH, concentration of extractant, shaking time and ionic strength. The maximum volume ratio of the aqueous to organic phase was 30:1 for a single-stage extraction of99-100% o...

Solutions of N,N,N’,N’,N”,N”-hexa-n-hexylnitrilotriacetamide (HHNTA) in 20 % isodecanol-80 n-dodecane (v/v) were employed for the supported liquid membrane (SLM) transport U(VI), Np(IV), and Pu(IV) from nitric acid feed solutions using PTFE (polytetrafluoroethylene) flat sheet membranes. Preliminary studies revealed poor U(VI) when compared with that tetravalent ions Np(IV) which may find appli...

Membrane extraction is a widely employed technique for improving the sensitivity and/or selectivity of a chemical analysis. This paper reports a study on the membrane extraction of aqueous transition metal ions using commercially available Nafion gas dryer assemblies. Though designed and marketed for use with gaseous mixtures, results of this work indicate such assemblies can be effective for t...

The ambipolar diffusion length and the minority-carrier mobility-lifetime products of microcrystalline hydrogenated germanium thin films, prepared by plasma enhanced chemical vapour deposition, are investigated by using the steady-state photocarrier technique. Different thin film samples were deposited with the dilution of the process gases, germane in hydrogen, GC = [GeH4]/[H2], between 0.2% t...

The effect of the separating extractant consumption on separation butene-divinyl fraction is considered