Solvent extraction of Zn/II/ with 1,2,3-benzotriazole into n-hepatanol

A method based on solvent extraction has been developed for the radiochemical separation of Zn/II/ from other elements employing 1,2,3-benzotriazole as a complexing agent and n-heptanol as an extractant. Optimum conditions for the extraction have been established. The effect of various anions and cations on the extraction coefficient value of Zn/II/ has been studied. The stoichiometry of the metal to reagent determined by the method of substoichiometric extraction and slope-ratio method was found to be 12.     

A study on the solvent extraction of Hg/II/ with 2-mercaptobenzothiazole into chloroform

The extraction of mercury/II/ with 2-mercaptobenzothiazole /2-HMBT/ into chloroform has been studied. The effect of various parameters on the extraction coefficient value such as effect of pH, time of equilibration, effect of anions and cations have been evaluated. The stoichiometry of the extracted species obtained by the method of substoichiometric extraction and slope ratio method was found to be 1∶2. Decontamination factors for a number of elements in the substoichiometric extraction of Hg/II/ were also obtained.     

Radiochemical separation of Pd/II/ with isonitrosobenzoylacetone in benzene

The reagent isonitrosobenzoylacetone /HINBA/ was used for the radiochemical separation of Pd/II/ employing solvent extraction. Based on various parameters such as effect of molarity of the acid, time of equilibration and effect of various solvents; the extraction coefficient value of Pd/II/ has been evaluated. The stoichiometry of the metal to reagent was determined by the substoichiometric extraction and slope-ratio method and was found to be 12.     

Radiochemical separation of Mn/II/ with 1,2,3-benzotriazole into 1-octanol employing solvent extraction technique

1,2,3-Benzotriazole /1,2,3-BT/ has been used for the radiochemical separation of Mn/II/ employing solvent extraction technique. Based on various parameters such as pH effect, time of equilibration and effect of various solvents, etc. the ideal conditions for the extraction of Mn/II/ was evaluated. The stoichiometry of the metal to reagent was determined by the substoichiometric extraction and slope-ratio method and found to be 12. The effect of anions on the extraction value of Mn/II/ revealed that a large number of anions do not interfere. Separation factors for various elements were also studied and the extraction found to be selective.     

Effect of photostability of mercury(II) dithizonate on photoacoustic spectroscopic determination of trace mercury

The solvent effect on the photostability of Hg(II) dithizonate in daylight and under laser irradiation has been confirmed and benzene found to be the best solvent to use in photometric work with Hg(II) dithizonate. A 1:1 v/v mixture of benzene and carbon tetrachloride is recommended for use in the laser-induced photoacoustic spectrometric determination of Hg(II) dithizonate. A detection limit of 0.8 ng/ml has been attained, together with a linear dynamic range of 3 orders of magnitude. Coupled with a concentration factor of 50 obtained by extraction, the method shows promise for the detection of Hg(II) at the 5-pg/ml level in water.     

Extraction-spectrophotometric determination of traces of copper(II), zinc(II), cadmium(II) and mercury(II) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol

Summary Sensitive extraction-spectrophotometric procedures are described for the complexes of Cu(II), Zn(II), Cd(II) and Hg(II) with 5-Br-PADAP using chloroform as solvent. Optimal conditions have been established for the quantitative extraction of the metal chelates and their composition and optical characteristics have been determined as well. The conditional extraction constants amount logK _ex=10, the molar absorptivities of the complexes being 10⁵ l·mole^–1·cm^–1. Job's method and equilibrium shift method indicate the molar ratios M5-Br-PADAP=12.

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Spektralphotometrische Bestimmung von Spuren Cu(II), Zn(II), Cd(II) und Hg(II) mit 2-(5-Bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP)

Zusammenfassung Einfache und empfindliche Methoden zur extraktionsspektralphotometrischen Bestimmung von Spuren Cu(II), Zn(II), Cd(II) und Hg(II) mit 5-Br-PADAP wurden beschrieben. Chloroform wurde als Extraktionsmittel verwendet. Die optimalen Bedingungen für die quantitative Extraktion der Metallchelate wurden ermittelt und deren Zusammensetzung bestimmt. Die Stabilitätskonstanten haben hohe Werte (logK _ex=10), die molare Absorption der Komplexe beträgt 10⁵1·mol^–1·cm^–1. Das Molarverhältnis der Komplexe beträgt M5-Br-PADAP=12.

     

Dispersive liquid-liquid microextraction of Fe(II) and Cu(II) with diethyldithiocarbamate and their simultaneous spectrophotometric determination using mean centering of ratio spectra

A new dispersive liquid-liquid microextraction (DLLME) method for preconcentration of trace quantities of Fe(II) and Cu(II) followed by their spectrophotometric determination has been developed. For the extraction, an appropriate mixture of ethanol (the disperser solvent) and carbon tetrachloride (the extraction solvent) was injected rapidly into the water sample containing Fe(II) and Cu(II) after formation of complexes with diethyldithiocarbamate. Mean centering (MC) of ratio spectra has been used for simultaneous determination of Fe(II) and Cu(II). Linear range of the method is 1.0–100 ng/mL for Fe(II) and 0.3–100 ng/mL for Cu(II), the detection limit is 0.53 ng/mL and 0.14 ng/mL Cu(II), resp. The interference effect of some anions and cations is reported. The method was applied to the determination of Fe(II) and Cu(II) in well water 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.     

Solvent extraction of Ni/II/ with isonitrosobenzoylacetone into chloroform

A method has been developed for the quantitative extraction of Ni/II/ with isonitrosobenzoylacetone /HINBA/ into chloroform. The effect of various parameters on the extraction coefficient value such as pH, time of equilibration, effect of solvents, anions, cations etc. have been studied. The stoichiometry of the metal: reagent determined by the method of substoichiometric extraction and slope ratio method was found to be 12. Decontamination factors for many elements in the substoichiometric extraction of Ni/II/ were also evaluated.     

A study on the solvent extraction of Cd/II/ with 1,2,3 benzotriazole into n-heptanol

The extraction of cadmium/II/ with 1,2,3 benzotriazole /2-BT/ into n-heptanol has been studied. The effect of various parameters such as effect of pH, time of equilibration, effect of anions on the extraction coefficient values have been evaluated. The stoichiometry of the extracted species by the method of substoichiometric extraction and slope ratio method was found to be 12. Decontamination factors for a number of elements in the substoichiometric extraction of Cd/II/ were also obtained.     

Radiochemical separation of Ru/III/ with 2-mercaptobenzothiazole into chloroform employing solvent extraction technique

The reagent 2-mercaptobenzothiazole /2-HMBT/ has been used for the solvent extraction of Ru/III/. The extraction coefficient value of Ru/III/ has been evaluated, based on various parameters such as, effect of molarity of the acid, time of equilibration, time of heating, effect of various solvents and effect of various salts. The stoichiometry of the metal to reagent was determined by the method of substoichiometric extraction of slope-ratio method and was found to be 13. Separation factor and decontamination factor for various elements have also been studied.     

Solvent extraction of Cu/II/ with 1,2,3-benzotriazole into chloroform

1,2,3-Benzotriazole/1,2,3-BT/ has been used for the extraction of Cu/II/ into chloroform. The effect of various parameters on the extraction coefficient of Cu/II/ was evaluated. The stoichiometry of metal:reagent, determined by the method of substoichiometric extraction and slope ratio was found to be 12. Separation factor for a number of elements in the extraction of Cu/II/ has been evaluated.     

Reversed phase partition chromatographic separation of divalent copper with N-n-octylaniline on silica gel

A novel separation method was developed for the extraction and chromatographic separation of copper(II). The quantative extraction of 25.0–125.0 μg copper(II) has been observed from 0.05 to 0.25 mol/L of ascorbic acid at pH 9.0–12.0 with 0.087 mol/L N-n-octylaniline (liquid anion exchanger) coated on silica gel at a flow rate of 1.0 ml/min. The extracted metal ion has been recovered by eluting with 25.0 ml of 1.0 mol/L hydrochloric acid and determined spectrophotometrically by rubeanic acid method. The various influencing parameters viz. acid concentrations, reagent concentration, eluates effect of pH, and effect of flow rate on extraction were studied. The method is free from large number of interferences from cations and anions. A scheme for mutual separation of copper(II), gold(III) and bismuth(III) has been developed. Copper(II) has been separated from ayurvedic (Herbal) medicine and synthetic mixtures corresponding to alloy. The log–log plot of N-n-octylaniline concentration versus the distribution coefficient indicates that the probable extracted species is [.     

GC-NPD investigation of the recovery of organonitrogen and organophosphorus pesticides from apple samples: The effect of the extraction solvent

Summary A gas chromatographic method employing a capillary column and a selective nitrogen/phosphorus detector (NPD) has been developed for the determination of organophosphorus (OP) and organonitrogen (NP) pesticides in horticultural samples (apples). The separation of sixteen pesticides and the internal standard was performed in thirteen minutes. The analytical characteristics of the method, including linear response ranges, detection limits, and reproducibility, have been studied using a 11 mixture of ethyl acetate and xylene as extraction solvent. The possibility of mutual interference between pesticides has also been studied. A procedure for the quantitative extraction of the sixteen pesticides from apple samples has also been developed; for fifteen of the pesticides recoveries >85% were obtained after 90 minutes extraction. The effect of different solvents both on recovery and on the sensitivity of the subsequent chromatography were also investigated. It was found that the sensitivity required must be considered when the solvent for sample treatment is selected.     

Spectrophotometric determination of Hg(II) in water samples by dispersive liquid liquid microextraction with use ionic liquid after derivatization with a water soluble Fe(II) phthalocyanine

This study reports the synthesis of water soluble iron(II) phthalocyanine and a facile method for spectrophotometric determination of Hg(II) in environmental water samples by ionic liquid based dispersive liquid–liquid microextraction (IL-DLLME). In the method, 1-heptyl-3-methylimidazolium hexafluorophosphate (250 µL) as extraction solvent, acetonitrile (750 µL) as dispersive solvent and Triton X-100 (200 µL) as anti-sticking agent were used. After the extraction of the Hg(II) complex (Hg(II):q-Fe(II)-Pc) into thin droplets of ionic liquid, the sample was centrifuged for 4 min at 2000 rpm. The upper aqueous phase was removed and the residue diluted to 250 µL with methanol and transferred to a 250 µL cell for spectrophotometric detection at 280 nm. The linear range of the method is 0.05–1 µg/mL. The limits of detection and quantification is 0.01 and 0.03 µg/mL, respectively. The RSD for the developed method was calculated as 0.78% at 0.50 µg/mL Hg(II).     

Solvent extraction of Co/II/ with isonitrosobenzoylacetone into chloroform

A rapid and selective method has been developed for the extraction of Co/II/ with isonitrosobenzoylacetone into chloroform. The effect of various parameters on the extraction coefficient value such as effect of pH, time of equilibration, effect of various cations and anions have been evaluated. The stoichiometry of metal to reagent determined by the method of substoichiometric extraction was found to be 12. It was further supported by the slope ratio method.     

Development of liquid-liquid extraction and separation method for ruthenium(III) with 2-octylaminopyridine from succinate media: Analysis of catalysts

Ruthenium(III) has been efficiently extracted from 0.05 M sodium succinate at pH 9.5 by 2-octylaminopyridine in xylene and stripped with aqueous 10% (w/v) thiourea solution and determined spectrophotometrically. Various parameters viz., pH, weak acid concentration, reagent concentration, stripping agents, contact time, loading capacity, aq.: org. volume ratio, solvent has been thoroughly investigated for quantitative extraction of ruthenium(III). The utility of method was analyzed by separating the ruthenium(III) from binary mixture along with the base metals like Cu(II), Ag(I), Fe(II), Co(II), Bi(III), Zn(II), Ni(II), Se(IV), Te(IV), Al(III) and Hg(II) as well as platinum group metals (PGMs). Ruthenium(III) was also separated from ternary mixtures like Os(VIII), Pd(II); Pd(II), Pt(IV); Pd(II), Au(III); Pd(II), Cu(II); Fe(II), Cu(II); Ni(II), Cu(II); Co(II), Ni(II); Se(IV), Te(IV); Rh(III), Pd(II); Fe(III), Os(VIII). The stoichiometry 1: 2: 1 (metal: succinate: extractant) of the proposed complex was determined by slope analysis method by plotting graph of logD _[Ru(III)] versus logC _[2-OAP] and logD _[Ru(III)] versus logC _[succinate]. The interference of various cations and anions has been studied in detail and the statistical evaluations of the experimental results are reported. The method was successfully applied for the analysis of ruthenium in various catalysts, synthetic mixtures corresponding to the composition of alloys and minerals.     

Suspended droplet solvent microextraction-flame atomic absorption spectrometry (SDSME-FAAS) determination of trace amounts of copper in river and sea water samples

A simple and sensitive suspended droplet solvent microextraction (SDSME) method is proposed for the preconcentration and determination of copper by flame atomic absorption spectrometry (FAAS). The analytical procedure is based upon the formation of a complex between Cu(II) and 1-phenyl-1,2-propandione-2-oxime-thiosemicarbazone (PPDOT) as a complexing agent. After extraction of the complex by 1-octanol, copper concentration in the solvent drop was determined by FAAS. The effect of different parameters such as pH, PPDOT concentration, kind of buffer, kind and volume of organic solvent, volume of aqueous phase, extraction time, stirring rate of sample solution, temperature, and ionic strength were investigated. The effect of foreign ions on the determination was also studied. Under the optimized chemical and instrumental conditions, a linear calibration curve was achieved in the range of 0.0050–0.26 mg/L, with the limit of detection of 3 μg/L and the enrichment factor of 52.6. This method can be applied successfully to the determination of copper in water samples.     

Substoichiometric isotope dilution analysis of arsenic in biological and environmental standard reference materials by solvent extraction using toluene-3,4-dithiol in benzene

A radiochemical solvent extraction procedure has been developed for the determination of As(III) using⁷⁶As tracer. It is based on the complexation of As(III) with toluene-3,4-dithiol (TDT) at pH 2 and subsequent extraction in benzene. The effect of various parameters such as pH, time of equilibration, nature of solvent, quantitative character and interferences have been studied. The method has been further developed into substoichiometric isotope dilution analysis for the determination of As at < 1 g level and employed for the analysis of several environmental and biological standard Reference Materials from NIST (USA), IAEA (Vienna) and NIES (Japan).     

Synergic effect of triphenylphosphine oxide (TPPO) on the extraction of Hg(II), Se(IV), Co(II) and Mn(II) with fluorinated pyrazolone (HPMTFP)

Extraction of Hg(II), Se(IV), Mn(II) and Co(II) has been carried out with 1-phenyl-3-methyl-4-trifluoroacetyl-2-pyrazolin-5-one (HPMTFP) and triphenylphosphine oxide (TPPO) into chloroform from pH 1–10. Quantitative extraction of Hg(II), Mn(II) and Co(II) at pH 4 with equimolar 0.05M (PMTFP+TPPO) in chloroform was observed. Se(IV) remains unextracted at this pH range. The stoichiometric composition of the extracted complexes M(PMTFP)₂·nH₂O (M=Mn, Hg), M(PMTFP)₂·2TPPO (M=Mn and Co) and Co(PMTFP)₂·TPPO·H₂O at less than 0.1M TPPO has been established. The formation constantsK _m,0 andK _m,n and stability constants _m,n have been computed. The analytical method developed was applied to the IAEA standard reference material (SRM) potato fluor V-4 for the determination of these elements using NAA technique.