The extraction of ferric chloride with methyl isobutyl ketone and amyl acetate

Summary The extraction of iron as ferric chloride in 7 M hydrochloric acid by a mixture of (1+1) or (2+1) methyl isobutyl ketone and amyl acetate is quantitative for macro as well as for micro amounts of iron. The distribution ratio is very high ( 4000). With these mixtures no emulsification difficulties are encountered as they are with methyl isobutyl ketone alone. The behaviour of 44 elements in this extraction has been investigated.     

Coulometric generation of hydrogen ions by oxidation of mercury in methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone

Mercury(II)-chloride reacts with anhydrous methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone in a precise stoichiometry ratio (1:2), and weakly ionized compounds of mercury with ketones are formed and equivalent quantity of HCl is released. The application of a mercury anode for the quantitative generation of H⁺ ions in 0.25 M sodium perchlorate in anhydrous methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone has been investigated. Current/potentials curves for the solvents, titrated bases, indicator and mercury showed that in these solvents mercury is oxidized at potentials much more negative than those for the titrated bases and other components present in the solution. The protons generated in this way have been used for the titration of some organic bases, with either visual or potentiometric end-point detection. The oxidation of mercury in methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone and the reaction of mercury ions with these solvents have been found to proceed with 100% current efficiency.     

Kinetics and mechanism of oxidation of acetone,ethyl methyl ketone and diethyl ketone with chloramine-T in hydrochloric acid medium

The kinetics of oxidation of aliphatic ketones (acetone, ethyl methyl ketone and diethyl ketone) by chloramine-T in presence of hydrochloric acid (0.1 to 0.3M) have been investigated at 30 °C. The rate of disappearance of chloramine-T has been found to be first order each with respect to oxidant, ketone and [H⁺], in the range of the acid concentrations studied. The thermodynamic and kinetic parameters have been evaluated by determining the rate constants at different temperatures. The products of the reaction have been identified as chloroketones by their NMR spectra. The solvent isotope effect has been studied in the case of the oxidation of acetone and ethyl methyl ketone. A mechanism has been proposed.     

Solvent extraction of Cd(II) with N-cyclohexyl-N-nitrosohydroxylamine and 4-methylpyridine into methyl isobutyl ketone

The distribution equilibria of the complexes cadmium-cnha and cadmium-cnha-4-methylpyridine in the water-methyl isobutyl ketone system have been studied at 25 degrees , by using (109)Cd as a radiotracer to measure the metal distribution ratio. A very sensitive method for detection of (109)Cd, based on the use of a liquid scintillator, has been developed. From the graphical treatment of the equilibrium data, it has been deduced that CdL(2) is the complex extracted in the absence of 4-methylpyridine, and that the adduct CdL(2)B is extracted when the second ligand is present. This model has been checked by treating the data with the program LETAGROP-DISTR and the following equilibrium constants have been obtained: stability constants of CdL(2), log beta(1) = 2.82 +/- 0.14, log beta(2) = 5.981 +/- 0.004; distribution constant of CdL(2), log K(DC) = -0.49 +/- 0.01; adduct formation constant of CdL(2)B, log K(s) = 2.70 +/- 0.07.     

Studies on the extraction and determination of metals-I Extraction of hafnium into methyl isobutyl ketone and tributyl phosphate

The effect of various factors on the distribution of hafnium ( 5.60 × 10⁻⁴M) between different acids and methyl isobutyl ketone (MIBK) or tributyl phosphate (TBP) was studied by using ^{176 + 181} Hf as a tracer, when the extraction is made from 7.5–11M hydrochloric acid with an equal volume of IM TBP in benzene, hafnium is extracted quantitatively (>99%). The hafnium can be stripped with 1–3M hydrochloric acid.     

Synthesis of chromogenic crown ethers and liquid-liquid extraction of alkali metal ions

New crown ethers carrying a pendent phenolic chromophore were synthesized. These crown ethers, on dissociation of the phenolic proton, provide lipophilic anions which can extract alkali metal cations into 1,2-dichloroethane by forming highly-colored uncharged metal complexes. Structural effects on the extraction were studied for possible use of these crown ethers as extraction—spectrophotometric reagents selective for alkali metals. The following factors are discussed in detail: (i) nature of the crown ether ring (ring size. aza-crown or standard crown ether), (ii) nature of the pendent phenolic group, and (iii) geometry between the crown ether center and pendent phenolic group. 15-Crown-5 or smaller ring-sized reagents favored the extraction of lithium ion when the basicity of the pendent phenolate was relatively high and a six-membered “chelate” ring was possible for the phenolate and the crown ether-bound metal. 15-Crown-5 type reagents were sodium-selective when an eight-membered “chelate” ring was possible between the phenolate and the crown ether-bound metal. 18-Crown-6 type reagents were generally potassium-selective. However, these selectivities were not absolute, and other structural parameters, steric and conformational, must be considered to explain in detail the selectivities of the individual reagents.     

Separation of ions by alteration of the concentration of the ligand in a discontinuous countercurrent extraction system

A new technique in Craig-type liquid-liquid, discontinuous, countercurrent solvent extraction was developed. In this, the ligand concentration in the extraction train was altered at several points, causing non-equivalent changes in the extractability of the ions being separated. This allowed quantitative separation of a mixture with a minimum number of transfers, thereby keeping the solvent volume to a minimum. The technique was applied to achieve total or partial separation of a number of elements, using methyl isobutyl ketone as the solvent and hydrochloric acid as the ligand. A computer programme was developed for calculating the distribution of a solute in an extraction train operating under these conditions.     

The application of 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane to the extraction of metal ions

The use of 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (Tet) in chloroform solutions provides quantitative extraction of lead(II), cadmium(II), copper(II) and zinc(II) at different pH values from solutions containing perchlorate and cyclohexanecarboxylic acid. Nickel(II) and cobalt(II) ions are not extracted quantitatively. Single extractions of mixtures of copper with transition metals gave the best separations for the copper/nickel system. Separations of copper from cobalt, lead, manganese and iron were less satisfactory.     

Studies on the extraction and determination of metal salts with isobutyl methyl ketone-XIV Extraction of gold

The isobutyl methyl ketone extraction of gold(III) from hydrochloric acid or various mixtures of hydrochloric and other mineral acids was studied as a function of the gold concentration and the acid concentration. Gold (initial concentration up to 5 x 10(-3)M) was quantitatively extracted (99%) from 3-5M hydrochloric acid. Addition of nitric acid in 1-5M concentration and sulphuric or perchloric acid in 1-3N concentration to the 1-5M hydrochloric acid solutions used had no effect.     

Equilibrium and kinetics of Zn(II) bromide extraction with Amberlite LA-2 and methyl isobutyl ketone

The rates of extraction of Zn(II) from hydrobromic acid solutions into benzene solutions of the liquid anion exchanger Amberlite LA-2 and those into methyl isobutyl ketone (MIBK) have been investigated. The distribution equilibria of this system have been also studied. Under the used experimental conditions the extracted species of Zn(II) have been proposed. The kinetic data indicated a first order reaction with respect to Zn(II) in both systems, nearly one with respect to HBr and from 0–0.38 for LA-2. In case of extraction of Zn(II) with methyl isobutyl ketone, MIBK, the reaction order with respect to MIBK was found to be 4 and with respect to HBr inverse first order. The rate constants of these extraction processes were determined and the rate determining steps were discussed in the light of the obtained results.     

The interaction between amino acids and metal ions (I). The FT-IR spectroscopic study of the binding between D,L-homocysteic acid and alkali metal ions

D,L-Homocysteic acid (DLH), an amino acid in the mammalian central nervous system, can excite the cerebral activities and has been proposed as an agonist of endogenous glutamate receptor. It contains -NH(3)(+), -COOH and -SO(3)(-) groups, therefore, the interactions between DLH and metal ions may be expected. In the present investigation, the complexes of DLH with NH4(+), Li+, Na+ and K+ at different pH conditions were synthesized and characterized by Fourier transform infrared (FT-IR) spectroscopy. It was concluded that the structures of the complexes prepared at pH 2.6 and 4.0 are similar to each other and the C=O groups are mono-dentate coordination for these complexes. However, the structures of the complexes synthesized at pH 13.0 change considerably from the complexes at pH 2.6 and 4.0, which show that dissociation has occurred in aqueous solution. The four cations coordinate to DLH, which result in the rearrangement of the hydrogen bond network and the skeletal structure change of the ligand.     

Calculations on partition equilibria in liquid-liquid extraction systems,applied to the separation of metal ions from aqueous solutions

A program has been developed for the calculation of partition equilibria in the case when metal ions are extracted from an aqueous phase into an immiscible organic solvent containing a chelating reagent. Given the extraction constants and the initial concentrations, titration curves are constructed which show the extraction percentage of each ion in the presence of the others. The program is applied to hypothetical situations both in activation analysis and isotope dilution analysis.     

Studies on the extraction and determination of metal salts with isobutyl methyl ketone-XIII Extraction of thorium and uranium

The work deals with the extraction of thorium or uranium from hydrochloric, perchloric, sulphuric or nitric acid solutions of various concentrations, or from mixed acid solutions, by means of isobutyl methyl ketone. When the extraction is made from 5-8M hydrochloric acid that is 10M in lithium chloride or from 7-8M hydrochloric acid that is 1M in magnesium chloride, uranium is extracted quantitatively (>99%), whereas thorium is hardly extracted at all.     

Fluorous ionic liquids as solvents for the liquid-liquid extraction of metal ions by macrocyclic polyethers

The predominant mode of strontium ion transfer from aqueous nitrate media into a series of 1-fluoroalkyl-3-methylimidazolium bis[(trifluoromethylsulfonyl)]imides containing dicyclohexano-18-crown-6 (DCH18C6) is shown to shift from cation exchange to strontium nitrato-crown ether complex partitioning as the length of the fluoroalkyl substituent is increased. Fluoroalkyl substituents are shown to be only slightly more effective than their non-fluorous analogs at inducing this shift. At the same time, the fluorinated ionic liquids (ILs) yield strontium distribution ratios as much as an order of magnitude lower than the corresponding 1-alkyl-3-methylimidazolium (C_nmim⁺) salts. Fluorous ILs thus appear to offer no compelling advantages over C_nmim⁺ ionic liquids as extraction solvents.     

Synthesis, characterization of MCM-22 and catalytic activity in one-step synthesis of methyl isobutyl ketone

Summary CPO of methane was studied over a range of pressures. Coke was observed at about 750 kPa but was avoided when gas-phase cooling was employed, allowing for operation at higher pressures.     

Simultaneous determination of odorous volatile organic compounds with gas chromatography and a thermal desorber: A case study on methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, toluene, and xylene

In this study, a series of experiments were conducted to examine the feasibility of the gas chromatographic approach for the quantification of several odorous volatile organic compounds (VOCs) in environmental samples which included methyl ethyl ketone, isobutyl alcohol, methyl isobutyl ketone, and butyl acetate plus benzene, toluene, and xylene (namely, BTX). The gaseous working standards (WS) of seven compounds were initially calibrated at varying concentration ranges by direct injection (DI) into GC injector. The detection properties of these compounds were then tested with a thermal desorber (TD). The relative sensitivities of three aromatic VOCs differed greatly between DI and TD methods. In contrast, four polar VOCs tend to consistently exhibit relative enhancement in response factors with increasing molecular mass (an exception of butyl acetate), regardless of method. The TD-based analysis was reliable enough to detect all target VOCs below their odor threshold values with their detection limit (DL) values. This TD method, when tested against a number of environmental samples collected from several industrial facilities, confirmed the presence of these odorous VOCs at a wide concentration range.     

the extraction of some metallic bromides from aqueous solutions with methyl ethyl ketone and methyl iso-butyl ketone

The extraction of the following metals from aqueous solutions containing excess bromide with methyl ethyl ketone (MEK), and methyl isobutyl ketone MIBK has been investigated:—Cu(I), Cu(II), Zn(II), Ni(II), Co(II), Fe(II), Fe(III), Al(III), Mn(II), Sn(II) and Sn(IV). The use of MEK was found to be strictly limited by its solubility in acidic aqueous solutions. Determinations of the formulae of the extracted compounds were attempted in two cases but were found to be not wholly satisfactory and were discontinued. An interesting reaction between the cupric bromide complex and the solvents was noticed. Separations of Fe(IIl) from Mn(II), Fe(III) from Al(III), Fe(III) from Co(Il) and Fe(III) from Ni(II) could be achieved under suitable conditions.