Study of the complex formation between 18C6 crown ether and Tl, Pb and Cd in binary non-aqueous solvents using differential pulse polarography

Rounaghi, Cholamhossein; Es’hagi, Zarrin; Ghiamati, Ebrahim

doi:10.1016/0039-9140(96)01857-7

Cited by 15 publications

(3 citation statements)

References 15 publications

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“…In similar investigations, authors used 4',4''(5'')-di-tert-butyldicyclohexano-18-crown-6 (DtBuDCH18C6) as a chelating agent for Pb(II) and suggest that various analogs of the 18C6 crown ethers family could be effective and selective for the CPE (24). Previous studies of stoichiometry and stability of Pb(II) complexes with 18C6 and similar ethers confirmed the stoichiometric ratio 1:1 and also higher stability of Pb(II) complexes compared to some other ions (28)(29)(30). At 1:2 stoichiometric ratio, the insufficient concentration of ligand leads to an underestimate of complexation of the metal, so the excess metal ions remain in solution.…”

Section: The Effect Of 18-crown-6 Concentrationmentioning

confidence: 93%

Cloud point extraction procedure for preconcentration and determination of lead(II) ions using triton X-100 at room temperature

et al. 2019

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A Cloud point extraction (CPE) procedure was presented for preconcentration of lead(II) ions, after complexation by 18-crown-6 (18C6) and extraction with Triton X-100 at proposed experimental conditions. After separation of surfactant-rich phase, content of Pb(II) ions in remaining solution was measured by Flame Atomic Absorption Spectrometry (FAAS). The experimental conditions such as pH, temperature, concentration of Triton X-100, concentration of 18C6, incubation time, type and concentration of added electrolyte, were evaluated. Results showed that among investigated electrolytes (NaCl, Na 2 SO 4 and Na 2 CO 3) the amount of 0.9 mol/L Na 2 CO 3 lowers cloud point temperature of Triton X-100 to 22°C (room temperature during the experiment), thus simplifying the extraction procedure. After an incubation time of 5 minutes and using the concentration of 1.2•10-3 mol/L Triton X-100 and 1.5•10-4 mol/L 18C6 (1:1 stoichiometric ratio for 18C6:Pb), 60% of lead (II) ions were efficiently removed from investigated solution.

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Section: The Effect Of 18-crown-6 Concentrationmentioning

confidence: 93%

Cloud point extraction procedure for preconcentration and determination of lead(II) ions using triton X-100 at room temperature

et al. 2019

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“…As a result, variations in the nature of the solvent produce significant changes in the binding properties of the ligand [8]. Various physiochemical methods have been used to obtain the stability constants of complexes [9][10].…”

Section: Introductionmentioning

confidence: 99%

Study of Complex Formation Constants for Some Cations With O-Phenylenediamine in Binary Systems Using Square Wave Polarography Technique

Nezhadali¹,

Hanieh²

2010

ENG

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The formation of metal cation complexes between o-phenylenediamine with metal ions, Ni2+, Cu2+, Zn2+, Pb2+ and Cr3+ were studied in the dimethylformamide/water(DMF/H2O), acetonitrile/water(AN/H2O) and ethanol/water(EtOH/H2O) binary systems using square wave polarography (SWP) technique. The stoichiometry and stability of the complexes were determined by monitoring the shifts in half-waves or peak potentials of the polarographic waves of metal ions against the ligand concentration. In the most cases, the formation constants of complexes decreased with increasing amounts of H2O, DMF and EtOH in AN/H2O, DMF/H2O and EtOH/H2O binary systems, respectively. The stoichiometry of the complexes was found 1:1. The results obtained show that there is an inverse relationship between the formation constant of the complexes and the donor number of the solvents based on the Gatmann donocity scale. Also, the stability constants show a high sensitivity to the composition of the mixed solvent systems. In most of the systems investigated, Cr3+ cation forms a more stable complex with o-phenylenediamine than other four cations and the order of selectivity of this ligand for cations in pure water is:Cr3+>>Cu2+>Ni2+>Zn2+>Pb2+

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“…There are several approaches concerning overcoming the In, Cd and Pb peaks' overlapping. This should include: liquid/liquid extraction before voltammetric analysis, 22,23 the addition of complexing agents or other substances increasing the difference between peaks' potentials, 13,24 instrumental or chemometric means [25][26][27] or proper choice of working electrode. 28 The lowest reported detection limit for indium ions determination was obtained with the use of mercury film electrode and was equal to 4.4 × 10 −12 mol L −1 (5 × 10 −4 ng mL −1 ).…”

mentioning

confidence: 99%

Sensitive Anodic Stripping Voltammetric Determination of Indium(III) Traces Following Double Deposition and Stripping Steps

Gęca

Korolczuk

2017

J. Electrochem. Soc.

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A procedure for the determination of In(III) by anodic stripping voltammetry following double deposition and stripping steps was described. Two environmentally friendly electrodes with different surface areas -glassy carbon macroelectrode and an ensemble of carbon composite microelectrodes -modified with bismuth films were used for the measurements. Parameters affected In(III) determination were optimized. Under optimized conditions the calibration graph was linear from 5 × 10 −10 to 2 × 10 −8 mol L −1 following deposition time of 300 s at both working electrodes. The application of double deposition and stripping steps led to a very low detection limit of indium determination of 1.5 × 10 −10 mol L −1 . Possible interferences from contaminant metal ions were studied and the procedure of elimination of Cd(II) effect on In(III) signal was proposed. The analysis of natural water sample was successfully performed with the use of the presented methodology.

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Study of the complex formation between 18C6 crown ether and Tl, Pb and Cd in binary non-aqueous solvents using differential pulse polarography

Cited by 15 publications

References 15 publications

Cloud point extraction procedure for preconcentration and determination of lead(II) ions using triton X-100 at room temperature

Cloud point extraction procedure for preconcentration and determination of lead(II) ions using triton X-100 at room temperature

Study of Complex Formation Constants for Some Cations With O-Phenylenediamine in Binary Systems Using Square Wave Polarography Technique

Sensitive Anodic Stripping Voltammetric Determination of Indium(III) Traces Following Double Deposition and Stripping Steps

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