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.     

Determination of Fe and Zn in biological samples by radiochemical neutron activation analysis

Radiochemical NAA methods have been developed for the simultaneous determination of Fe and Zn in biological samples. The method involves reactor irradiation, dissolution in 3M HCl and solvent extraction followed by counting on a scintillation gamma-ray spectrometer. Iron was separated with aqueous cupferron and extracted into chloroform while Zn was extracted with 2-thenoyl trifluoroacetone (TTA) into methyl isobutyl ketone (MIBK). Reaction conditions such as pH and the effect of solvents and various ions were studied using tracer activities. The methods have been employed for trace level determination of Fe and Zn in NBS, SRMs, Bowen's Kale, IAEA CRMs and other plant leaves.     

Removal of iron interferences by solvent extraction for geochemical analysis by atomic-absorption spectrophotometry

Iron is a common interferent in the determination of many elements in geochemical samples. Two approaches for its removal have been taken. The first involves removal of iron by extraction with methyl isobutyl ketone (MIBK) from hydrochloric acid medium, leaving the analytes in the aqueous phase. The second consists of reduction of iron(III) to iron(II) by ascorbic acid to minimize its extraction into MIBK, so that the analytes may be isolated by extraction. Elements of interest can then be determined using the aqueous solution or the organic extract, as appropriate. Operating factors such as the concentration of hydrochloric acid, amounts of iron present, number of extractions, the presence or absence of a salting-out agent, and the optimum ratio of ascorbic acid to iron have been determined. These factors have general applications in geochemical analysis by atomic-absorption spectrophotometry.     

Influence of the solvent on the extraction of copper(II) from nitrate medium using salicylideneaniline

Different solvents including cyclohexane, dichloromethane, chloroform, toluene, 1-octanol, and methyl isobutyl ketone (MIBK) have been evaluated in extracting copper(II) from nitrate medium by salicylideneaniline. Extracted species differs from solvent to solvent: CuL₂ in cyclohexane, toluene, 1-octanol, and methyl isobutyl ketone. However, in dichloromethane or chloroform, there are two complexes of the type CuL₂ and CuL₂(HL). The extraction constants and percentage of extraction (%E) are calculated for different solvents. Solvent played an important role in recovering copper(II) from the aqueous solution, thus affecting the extraction equilibrium and extraction efficiency. The nonpolar solvent showed better performance than the polar solvent. The maximum extraction efficiency was 85.75% at pH?=?4.5, which was from cyclohexane.     

Extraction of palladium and platinum with trioctylphosphine oxide (TOPO) in various solvents from hydrochloric and hydrobromic acid media

The extraction of palladium and platinum with trioctylphosphine oxide (TOPO) in cyclohexane, chloroform, methyl isobutyl ketone (MIBK) and 2,2′-dichlorodiethyl ether (DCDE) from hydrochloric and hydrobromic acids in dependence on the concentration of the acids and the extractant has been investigated. The obtained relation have been discussed and the possibilities of the separation of palladium, platinum, gold and their simultaneous extraction have been pointed out.     

Solvent extraction of metals with commercial oxime extractant (LIX 622)

The extraction characteristics of some selected metals from an aqueous buffered solution by LIX 622, a commercial oxime extractant have been studied. The pH_1/2 values for extracting different metals with 5 v/v% LIX 622 extractant in methyl isobutyl ketone (MIBK) have been obtained. The order of extraction of metals with LIX 622 extractant as a function of pH_1/2 value is determined and results agree well with the order obtained using salicylaldoxime as chelating ligand for the extraction of these metals.     

Kinetics of iron(III) bromide extraction with n-tributyl phosphate

The equilibrium and rate of solvent extraction of FeBr₂ complexes from HBr solutions into benzene solutions of tributyl phosphate (TBP) have been investigated. It is found that two reactions control the iron(III)-TBP extraction from hydrobromic acid solutions. From HBr activity of 1.2–1.55 (molarity based) the reaction is inverse third order with respect to the aqueous phase acidity. From HBr activity of 1.7–6 (molarity based) the reaction is first order in HBr concentration in the aqueous phase. Both of these reactions are first order for both Fe(III) and TBP. The rate constants for these reactions were calculated and the rate-controlling steps are discussed.     

Extraction and Flameless AAS Determination of Germanium in Lignite Fly Ash

Abstract

The use of dicyclohexyl-18-crown-6 methyl isobutyl ketone solution in extraction and flamelessatomic absorption spectrophotometry (AAS) determination of germanium in lignite fly ashes have been studied.

Germanium is usually determined in lignites after the carbonaceous part of the sample has been burnt by a dry or wet ashing method. However, methods are described for direct determination of germanium.

In the present paper a wet ashing method is reported for the determination of germanium in lignite fly ashes by flameless AAS after extraction into dicyclohexyl-18-crown-6 methyl isobutyl ketone (MIBK) solution. Solvent extraction is a known hydrometallurgical method that could be applied in germanium recovery.     

悬液电极萃取碘伏安法的研究

分别以硝基苯(NB)、苯乙酮(ACP)、4-甲基-2-戊酮(MIBK)三种不同的有机溶剂作为悬液电极, 利用三电极体系伏安法比较其在液/液界面上对碘的不同的电化学特性. 在上述研究的基础上, 选用MIBK作为有机溶剂对碘进行萃取分析, 利用伏安法测定了水溶液中Cu(II)的含量, 同时研究了温度和萃取时间对该体系的影响.     

Countercurrent extraction separation of some platinum group metals: part III

The bromo complexes of platinum(IV), palladium(II), rhodium(III), and iridium(IV) were prepared and studies were made on their distribution between hydrobromic acid solutions and various common solvents. The solvents employed were n-tributyl phosphate (TBP), methyl isobutyl ketone, amyl acetate, and various TBP-benzene mixtures. Distribution coefficients as a function of HBr concentration are given for each metal for each solvent system. A careful study of the measured distribution coefficients clearly showed that a number of binary and ternary mixtures of the metals can be resolved with a Craig countercurrent distribution apparatus. Rh-Pt and Rh-Pd mixtures in 4.38M HBr solutions were quantitatively separated on a Io-stage Craig apparatus using a 90% TBP-10% benzene solvent. Rh-Ir mixtures in 4.38 M HBr were resolved by 3 consecutive batch extractions with 90% TBP-10% benzene. Mixtures of Pd, Rh, and Ir in 4.38 M HBr were resolved in 90 stages using methyl isobutyl ketone as the solvent. Pd, Rh and Ir were recovered in 97.0, 87.6 and 94.5% yields, respectively. Mixtures of Pd, Rh and Pt in 4.38 M HBr were resolved in 90 stages using amyl acetate and methyl isobutyl ketone as solvents. Pd, Rh and Pt were recovered in 90.0, 96.0 and 94.0% yields, respectively. Two computer programs for the IBM 1620 Computer are given ; these facilitate the comparison of theoretical and actual solute distributions.     

Simultaneous determination of tartrazine,riboflavine, curcumin and erythrosine by derivative spectrophotometry

A quaternary mixture of Tartrazine (E-102), Riboflavine (E-101), Curcumin (E-100) and Erythrosine (E-127) can be analysed, by means of a previous extraction step using methyl isobutyl ketone (MIBK) as extracting agent, and resolving the binary mixtures obtained in the aqueous and organic phases by derivative spectrophotometry with measurements at the “zero-crossing” wavelengths and by derivative ratio spectra. The established conditions of extraction and the proposed methods have been applied to determine these colorants in several synthetic mixtures with good recoveries.     

Selective back-extraction and preconcentration of zinc(II) from metal-1,3,5-triketone extracts prior to its determination by flame atomic absorption spectrometry

A simple back-extraction method was developed for the separation and preconcentration of trace levels of zinc from different matrices. Ethyl-2-(4-methoxybenzoyl)-3-(4-methoxyphenyl)-3-oxopropanoylcarbamate (EMPC) was used as a new complexing agent for the extraction of zinc(II) from the aqueous sample phase to the methyl isobutyl ketone (MIBK) phase as Zn(EMPC)₂ complexes. The Zn(II) can be selectively stripped with 1?mL of 0.5?mol?L^?1 HCl from Mⁿ⁺(EMPC)_n complexes [Ag(I), Al(III), Cd(II), Cr(III), Cu(II), Fe(II), Fe(III), Mn(II), Ni(II), Pb(II) and Pd(II)] which dissolved in MIBK phase. Some experimental parameters, which are important for the whole extraction process, including pH, sample volume, shaking time, amount of the EMPC reagent, amount of MIBK, ionic strength, and type of back-extractant were investigated. The recovery for Zn(II) was greater than 95%. The detection limit of the method was found to be 0.2?µg?L ^{? 1} and the relative standard deviation as 6.4%. The concentrations of Zn(II) in the certified reference materials (LGC6019 river water and NIST-1547 peach leaves) by the presented method were in good agreement with the certified values. The proposed method was succesfully applied to the determination of zinc in some natural waters, rice, hair, soil, and tea samples.     

A study on the solvent extraction of Pd/II/ with 1,2,3-benzotriazole into methyl iso-butyl ketone

A novel method has been developed for the extraction of Pd/II/ with 1,2,3-benzotriazole /1,2,3-BT/ into methyl isobutyl ketone /MIBK/ at a pH of 4.0. The effects of pH, time of equilibration, solvent, anions and cations on the extraction coefficient have been evaluated. The stoichiometry of the extracted species of 12 was obtained by the slope ratio method and by the method of substoichiometric extraction. Separation factors and decontamination factors for a number of elements in the extraction of Pd/II/ were also obtained.     

Quantitative goldbestimmung in filmmaterialien mittels flammenloser atomabsorption

A graphite rod electrothermal atomizer has been used for the AAS determination of traces of gold in hydrochloric and in hydrobromic acid solutions, and also after extraction into HBr-saturated methyl isobutyl ketone. Photographic film samples were decomposed first by enzyme action then by nitric acid/peroxide oxidation, and the gold was extracted into MIBK. For 10-μl aliquots of solution the 3s limits of detection were 3 × 10^?10g for aqueous solutions, 7 × 10^?10g for MIBK, and 7 × 10^?9 g/cm² for film.     

Mechanism of oxidation of some aliphatic ketones by N-bromosuccinimide in acidic media

Kinetics of the oxidation of methyl n-propyl ketone and methyl isobutyl ketone by N-bromosuccinimide (NBS) have been studied in perchloric acid media in presence of mercuric acetate. A zero order dependence to N-bromosuccinimide and a first order dependence to both ketones and hydrogen ion concentrations have been observed. Sodium perchlorate, mercuric acetate and succinimide additions have negligible effect while methanol addition has a positive effect on the reaction rate. A solvent isotope effect (k₀D₂O/K₀H₂O = 2.3-2.7 and 2.4-2.8 for MeCOn.pr and MeCoi-Bu, respectively) has been observed at 35°. Kinetic investigations have revealed that the order of reactivity is methyl n-propyl ketone > methyl isobutyl ketone. Various thermodynamic parameters have been computed and corresponding 1,2-diketones were found to be the products. A suitable mechanism in conformity with the above observations has been proposed.     

电感耦合等离子体光谱法测定高纯镓中的痕量元素

比较了乙醚和甲基异丁基酮（MIBK）两种萃取剂对高纯镓中基体与杂质的分离效果。选择MIBK作为萃取剂,将高纯镓中的基体元素镓萃入有机相,绝大多数金属杂质则留在水相中,用电感耦合等离子体发射光谱法测定了水溶液中 的14种痕量元素。方法的加标回收率为805－110％,检出限在0.001-0.075ug/mL之间。     

Flame atomic absorption spectrometry of silver and gold in copper intermediates

The effect of hydrochloric acid and salts from the sample on the solubility of methyl isobutyl ketone (MIBK) in aqueous phase and the effect of hydrochloric acid concentration on the MIBK extraction of iron(III) and gold(III) were studied. As a result, an improved method by flame atomic absorption sepctrometry for determination of silver and gold in copper intermediates was developed, employing a more efficient removal of iron and special standards depending upon the concentration of salts introduced by different samples.     

Solvent extraction of metals using LIX26 extractant

Solvent extraction of some selected metals from an aqueous buffered solution by LIX26 extractant has been studied. The pH_1/2 values (at which 50% of metal ion is extracted) for extracting different metals by 1 v/v% LIX26 extractant in methyl isobutyl ketone have been obtained. The order of extraction of metals by LIX26 extractant as a function of pH_1/2 value is Pd(II)<Cu(II)<Sb(III)<Fe(II)<Co(II)<Zn(II)<Ni(II) <Pb(II)<Mn(II)<Cd(II).     

APDC-MIBK extraction system for the determination of trace elements in saline waters by atomic-absorption spectrophotometry

A technique has been developed for the determination of "soluble" cobalt, copper, iron, lead, nickel and zinc in saline waters by simultaneous extraction of their complexes with ammonium pyrollidine dithiocarbamate (APDC) into methyl isobutyl ketone (MIBK) and subsequent analysis by atomic-absorption spectrophotometry. Particulate matter is analysed separately by dissolving millipore filters in an acetone-hydrochloric acid mixture. Various analytical and instrumental parameters have been evaluated. The method is selfcompensating in that it makes allowance for any incomplete extraction of the complexes. The technique has been applied to the determination of these elements in sea-water and saline lakes.     

Atomic-absorption spectrophotometric determination of traces of manganese with thenoyltrifluoroacetone

An atomic-absorption spectrophotometric method for the determination of traces of manganese in solution with thenoyltrifluoroacetone (TTA) is described. Manganese(II) is extracted with 0.01M TTA in methyl isobutyl ketone (MIBK) at pH 9.5. The atomic-absorption of the organic phase at 279.5 nm is measured. Except for chromium, iron, hafnium, niobium, nickel, rhodium, tin, titanium and zirconium, microquantities of many other cations and anions do not interfere. Iron can be removed by MIBK extraction before the TTA extraction. The sensitivity of the method was 1.6 ng/ml for 1% absorption in aqueous solution. The method was successfully applied to the analysis of environmental waters. Manganese in the filtered fractions of water samples was reliably determined with relative standard deviations of 7% at the 5 mug/l. level and 1% at 50 mug/l.