scholarly journals SORPTION-DESORPTION MECHANISM OF Zn(II) AND Cd(II) ON CHITIN

2010 ◽  
Vol 6 (1) ◽  
pp. 47-51
Author(s):  
Sri Juari Santosa ◽  
Narsito Narsito ◽  
Aldes Lesbani
Keyword(s):  
Metal Ions ◽  
Chelating Agent ◽  
Acid Property ◽  
Portunus Pelagicus ◽  
First Order ◽  
Sorption Energy ◽  
Langmuir Isotherm Model ◽  
Desorption Experiment ◽  
Desorption Mechanism

This study reports the results of the elucidation of the sorption-desorption mechanism of Zn(II) and Cd(II) on chitin through the determination of capacity, energy, and rate constant of sorption as well as the investigation of their desorption properties in NaCl and Na2EDTA solutions. The chitin was isolated through deproteination followed by demineralization of crab (Portunus pelagicus Linn) shell using NaOH solutions. The sorption of both metal ions followed the Langmuir isotherm model, resulting the sorption capacities of 3.2 x 10-4 and 2.8 x 10-4 mol g-1 for Zn(II) and Cd(II), respectively, and sorption energies of 15.1 kJ mol-1 for Zn(II) and 17.9 kJ mol-1 for Cd(II). It was also observed that Zn(II) was sorbed slightly faster than Cd(II) with first order sorption rate constants of 2.82 x 10-3 min-1 for Zn(II) and 2.61 x 10-3 min-1 for Cd(II). The result of the desorption experiment showed that Cd(II) and especially Zn(II) could only be exchanged by Na(I) after desorbing those metal ions by strong chelating agent of EDTA2-. The easier desorption of Zn(II) than Cd(II) by EDTA2- must be attributed by the smaller sorption energy of Zn(II) and by harder acid property of Zn(II) than Cd(II) as EDTA2- contained hard electron donor elements.   Keywords: sorption, desorption, chitin, Zn(II), Cd(II)

scholarly journals Cloud Point Extraction for the Determination of Different Metal Ions by Using Bis(2-Acetyl Pyridine 4-Phenyl 3-Thiosemicarbazone) as Complexing Reagent

2019 ◽  
Vol 62 (2) ◽  
pp. 76-81
Author(s):  
Ambreen Shah ◽  
Fayyaz Ahmed Keerio ◽  
Saima Qayyum Memon ◽  
Ghulam Zuhra Memon
Keyword(s):  
Metal Ions ◽  
Cloud Point ◽  
Cloud Point Extraction ◽  
Sodium Dodecyl ◽  
Chelating Agent ◽  
Absorption Spectrometry ◽  
Micellar Phase ◽  
Flame Atomic Absorption ◽  
Effects Of Ph

A new method of cloud point extraction was determined for preconcentration and determination of different metal ions like copper(II), nickel(II) and cobalt(II) ions. The complexation has been done by bis(2-acetyl pyridine 4-phenyl 3-thiosemicarbazone) (APPT) using sodium dodecyl sulphate (SDS) as surfactant. Metal ions are extracted into the phase rich in SDS after centrifugation. Initially, micellar phase was dissolved in 10 mL of deionized water then acidified with 0.5 mol/L HNO3, enhanced the surfactant- rich phase and analyzed by flame atomic absorption spectrometry (FAAS). The effects of pH, the concen- trations of metal ions and chelating agent (APPT), volume of surfactant (SDS), equilibration temperature and time were studied on CPE. The preconcentration factor obtained was 25 and the limits of detection(DL) obtained for cobalt(II), nickel(II) and copper(II) were 1.5, 1.7 and 2.4 ng/mL, respectively. This method of preconcentration was effectively useful for the determination of cobalt(II), nickel(II) and copper(II) in water samples.

scholarly journals Fractional Derivatives for Description of Sorption Kinetics in the Plant Sorbent - Metal Ions System

2013 ◽  
Vol 20 (3) ◽  
pp. 499-506 ◽  
Author(s):  
Elwira Tomczak ◽  
Władysław Kamiński ◽  
Dominika Szczerkowska
Keyword(s):  
Metal Ions ◽  
Fractional Derivatives ◽  
Computational Procedure ◽  
Sorption Kinetics ◽  
Kinetics Equation ◽  
Gamma Functions ◽  
First Order ◽  
Two Parameters ◽  
Result Analysis

Abstract It was examined if buckwheat hull has a potential to be used to adsorb heavy metal ions Zn(II), Cd(II), Co(II), Cu(II), Ni(II) from water. The research involved experiments aimed at the determination of sorption kinetics taking into consideration changes of concentration in a solution and sorbent over time. According to the literature data, kinetics is described with the use of pseudo first-order equations. Application of fractional derivatives for the description of sorption kinetics enables the development of the generalised sorption kinetics equation. Result analysis with this concept requires making a computational procedure using gamma functions and infinite series. Kinetics description using fractional derivatives will be equations with two parameters ie fraction of derivative α and the kinetics constant K dependent on the analysed sorbent-adsorbate system.

scholarly journals Extractive Spectrophotometric Determination of Pd(II) with Sodium Salt of Hexamethyleneiminecarbodithioate

2013 ◽  
Vol 23 ◽  
pp. 20-28
Author(s):  
S.D. Dhanavate ◽  
D.J. Garole ◽  
V.J. Garole ◽  
S.R. Tetgure ◽  
A.D. Sawant
Keyword(s):  
Metal Ions ◽  
Spectrophotometric Determination ◽  
Sodium Salt ◽  
Accurate Determination ◽  
Chelating Agent ◽  
Molar Absorptivity ◽  
Real Samples ◽  
Highly Sensitive ◽  
Ph Range

The reagent NaHMICdt·2H2O has found to be a good chelating agent for the spectrophotometric determination of various metal ions. The present investigation deals with spectrophotometric determination of Pd(II) by using NaHMICdt·2H2O. The reagent reacted with Pd(II) to give yellow complex extractable into toluene. Pd (II) was extracted quantitatively in the pH range 0.5-2.0. Pd(II)-HMICdt complex showed λmax at 435 nm. The extracted species has a 1:2 (M:L) stoicheometry. Beer’s law is obeyed in the range of 0.2-0.8 μg ml-1 of Pd (II). The molar absorptivity and the sandells sensitivity were found to be 0.754 x 104 lmol-1cm-1 and 0.0140 μg mol-1 cm-2 respectively. The effect of divers ion on the extraction of Pd(II) has been investigated. The proposed method is highly sensitive, selective, and simple and rapid has been applied for accurate determination of palladium in synthesis mixtures and real samples.

Spectrophotometric Determination of Cu2+ Metal Ions via Complex Formation with Carboxylated Tris(2-aminoethyl)amine

2016 ◽  
Vol 12 (3) ◽  
pp. 4237-4246
Author(s):  
Imad Odeh ◽  
Ibrahim Abu Shqair ◽  
Ziad M Shakhshir ◽  
Julnar Masharqah ◽  
Waheed J Jondi
Keyword(s):  
Standard Deviation ◽  
Complex Formation ◽  
Metal Ions ◽  
Chelating Agent ◽  
Variation Method ◽  
Relative Standard ◽  
Continuous Variation Method ◽  
The Stability ◽  
Aminopolycarboxylic Acid

An aminopolycarboxylic acid chelating agent; tris(2-aminoethyl)aminehexaacetic acid (TAHA) was prepared and characterized. TAHA formed stable complexes with Cu(II) ions and other metal ions at pH 10. The complexation behavior was studied by spectrophotometry at the complex maximum wavelength. Mixtures of Cu(II) and other metal ions (M2+; Ca2+, Co2+, Ni2+, Cd2+)were titrated with TAHA at pH 10. The stoichiometry of ligand - to - metal was found to be 1:1. The stability constant of Cu(II)–TAHA complex was determined to be 1.86×105 by using the continuous variation method. Beer’s law was obeyed over the concentration range 3.0×10–4 M – 1.2×10–2 M for Cu(II) solution. The results of the quantitative determination of Cu(II) gave LOD and LOQ values of 7.285×10–6 M and 2.428×10–5 M respectively. The percent relative standard deviation (%RSD) for five replicate samples was found to be 1.088% and 4.804% for Cu(II) concentrations of 1.2×10–2 M and 3.0×10–4 M respectively.

scholarly journals Composition and stability of complexes of Ephedrine hydrochloride with Ni2+, Zn2+, and Cd2+ as toxic ions

2003 ◽  
Vol 71 (2) ◽  
pp. 75-88
Author(s):  
Nabawia EL Guindi
Keyword(s):  
Metal Ions ◽  
Chelating Agent ◽  
Cadmium Ions ◽  
Nickel Zinc ◽  
Ephedrine Hydrochloride ◽  
Stability Of Complexes ◽  
Different Temperatures ◽  
The Stability

The complexes of Ephedrine with Nickel, Zinc and Cadmium ions have been investigated spectrophotometricalfy using the method of corresponding solutions [I-3] and pH-metrically using Irving and Rossoti technique [4] Two compositions were observed spectrophotometrically 1 : 1 and 2: 1 (L: M) for concentration of metal ions (0.5 x 10-3 M and 1 x 10-3 M) hile the first composition only predominate at concentration of metal ions (1.5 x 10-3 M and 2 x 10-3 M ). The stability of complexes show that complexes of Ni2+ are more stable than that of Zn2+ an Cd2+, Moreover, the composition and stabilities of complexes were studied pHmetrically in aqueous medium at 0.1 M NaCl and two different temperatures 30°C and 40°C; hence the value of the free energy change (ΔG°), the enthalpy (ΔH°) and the entropy (ΔS°) were calculated at 30°C. Beside the role of Ephedrine as chelating agent to toxic elements, the complexometric method was used for the determination of Ephedrine in its pure form and in tablets.

Antithrombin-mediated Inhibition of Factor Vlla-Tissue Factor Complex by the Synthetic Pentasaccharide Representing the Heparin Binding Site to Antithrombin

1996 ◽  
Vol 76 (01) ◽  
pp. 005-008 ◽  
Author(s):  
Jean Claude Lormeau ◽  
Jean Pascal Herault ◽  
Jean Marc Herbert
Keyword(s):  
Binding Site ◽  
Tissue Factor ◽  
Residual Activity ◽  
Coagulation Factors ◽  
Heparin Binding ◽  
Experimental Conditions ◽  
First Order ◽  
Heparin Binding Site ◽  
Coagulant Activity

SummaryWe examined the effect of the synthetic pentasaccharide representing the minimal binding site of heparin to antithrombin on the antithrombin-mediated inactivation of factor Vila bound to tissue factor. This effect was compared to the effect of unfractionated heparin. Using purified recombinant human coagulation factors and either a clotting or an amidolytic assay for the determination of the residual activity of factor Vila, we showed that the pentasaccharide was an efficient antithrombin-dependent inhibitor of the coagulant activity of tissue factor-factor Vila complex. In our experimental conditions, assuming a mean MW of 14,000 for heparin, the molar pseudo-first order rate constants for ATIII-mediated FVIIa inhibition by ATIII-binding heparin and by the synthetic pentasaccharide were found to be similar with respective values of 104,000 ± 10,500 min-1 and 112,000 ± 12,000 min-1 (mean ± s.e.m., n = 3)

Statistical method of steepest improvement of response

2018 ◽  
Vol 84 (11) ◽  
pp. 74-87
Author(s):  
V. B. Bokov
Keyword(s):  
Statistical Method ◽  
Linear Model ◽  
Response Prediction ◽  
Initial Experiment ◽  
First Order ◽  
Prediction Response ◽  
Conditional Extremum ◽  
Order Polynomial ◽  
Limiting Values

A new statistical method for response steepest improvement is proposed. This method is based on an initial experiment performed on two-level factorial design and first-order statistical linear model with coded numerical factors and response variables. The factors for the runs of response steepest improvement are estimated from the data of initial experiment and determination of the conditional extremum. Confidence intervals are determined for those factors. The first-order polynomial response function fitted to the data of the initial experiment makes it possible to predict the response of the runs for response steepest improvement. The linear model of the response prediction, as well as the results of the estimation of the parameters of the linear model for the initial experiment and factors for the experiments of the steepest improvement of the response, are used when finding prediction response intervals in these experiments. Kknowledge of the prediction response intervals in the runs of steepest improvement of the response makes it possible to detect the results beyond their limits and to find the limiting values of the factors for which further runs of response steepest improvement become ineffective and a new initial experiment must be carried out.

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