scholarly journals Preconcentration of Cr(III) from Natural Water by Modified Nano Polyacrylonitrile Fiber by Methanolamine

2011 ◽  
Vol 8 (3) ◽  
pp. 1052-1061
Author(s):  
Ali Moghimi
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Tap Water ◽  
Selective Extraction ◽  
Polyacrylonitrile Fiber ◽  
Chemically Modified ◽  
Flame Atomic Absorption ◽  
Preconcentration Factor ◽  
The Stability ◽  
Acrylic Fibers

Modified nano polyacrylonitrile fiber (PANF) was prepared by adding acrylic fibers to methanolamine (MMA) with different concentration solutions. The stability of a chemically modified nano polyacrylonitrile fiber especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of modified nano polyacrylonitrile fiber. The application of this modified nano polyacrylonitrile fiber for sorption of a series of metal ions was performed by using different controlling factors such as the pH of metal ion solution and the equilibration shaking time by the static technique. Cr(III) was found to exhibit the highest affinity towards extraction by these modified nano polyacrylonitrile fiber phases. The pronounced selectivity was also confirmed from the determined distribution coefficient (Kd) of all the metal ions, showing the highest value reported for Cr(III) to occur by modified nano polyacrylonitrile fiber. The modified nano polyacrylonitrile fiber for selective extraction of Cr(III) were successfully accomplished in aqueous solution as well as preconcentration of low concentration of Cr(III) (60 pg mL-1) from natural tap water with a preconcentration factor of 100 for Cr(III) and then off-line Cr(III) in water samples were determined by flame atomic absorption.

scholarly journals Inhibition of enzymes by metal ion-chelating reagents. Theory and new graphical methods of study

1974 ◽  
Vol 137 (1) ◽  
pp. 55-60 ◽  
Author(s):  
William G. Bardsley ◽  
Robert E. Childs
Keyword(s):  
Stability Constant ◽  
Metal Ions ◽  
Metal Ion ◽  
Graphical Methods ◽  
Ligand Interaction ◽  
Mechanism Of Inhibition ◽  
The Stability ◽  
Chelating Reagents

1. The mechanism of inhibition of enzymes by metal ion-chelating reagents is discussed and equations derived. 2. Two distinct mechanisms are postulated and graphical methods are given for differentiating between them. 3. Where the metal ion is actually removed from the enzyme to form a co-ordination complex in solution, a procedure is described for obtaining the stability constant for metal–enzyme interaction, the number of metal ions involved and the stoicheiometry of metal ion–ligand interaction.

Changes in aggregate stability and associated organic matter properties after direct drilling and ploughing on some Australian soils

Soil Research ◽  
1980 ◽  
Vol 18 (1) ◽  
pp. 27 ◽  
Author(s):  
AP Hamblin
Keyword(s):  
Metal Ions ◽  
Aggregate Stability ◽  
Selective Extraction ◽  
Continuous Cropping ◽  
Neutral Salt ◽  
Structural Improvement ◽  
Trivalent Metal Ions ◽  
Direct Drilling ◽  
The Stability ◽  
Humic Fractions

After 3-8 years' continuous cropping with conventional cultivation and direct drilling, five Australian soils were examined for changes in structural stability attributable to tillage methods. Some increase in organic carbon was found in four direct drilled soils, and the proportion of carbon in the greater than 2 �m fractions was also higher in these soils after short ultrasonic treatment. Direct drilled soils had significantly greater stability with at least one of the stability tests used, but no soil showed consistently greater stability to five different tests. One direct drilled soil was more stable than its ploughed equivalent after alkaline and neutral salt extraction of metal ions and associated humic substances. One direct drilled soil was more dispersed by polysaccharide extraction. Three direct drilled soils retained greater stability after selective extraction of trivalent metal ions complexed to humic fractions. Structural improvement takes place in Australian soils after several years of direct drilling, but may be at a slower rate and to a lesser extent than has been reported for wetter environments.

scholarly journals PENGEMBANGAN METODE CITRA DIGITAL BERBASIS APLIKASI ANDROID UNTUK ANALISIS ION LOGAM Cr(VI)

Alotrop ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 117-124
Author(s):  
Marti Hitsmi ◽  
Mochamad Lutfi Firdaus ◽  
Nurhamidah Nurhamidah
Keyword(s):  
Metal Ions ◽  
Digital Image ◽  
Water Samples ◽  
Metal Ion ◽  
Limit Of Detection ◽  
Tap Water ◽  
Inductively Couple Plasma ◽  
Image Method ◽  
Complex Method ◽  
Conventional Methods

The presence of heavy metals in the environment can be a serious problem because it is harmful to human health. One of the heavy metal ions that pollute the environment is the Cr6+ metal ion. The usual tool used to analyze metal ions is Cr6+ is the Atomic Absorption Spectrometry (AAS) and Inductively Couple Plasma (ICP) which are very expensive and require trained personnel. The purpose of this study was to design a simple detector for Cr6+ metal ions as an alternative to conventional methods using AAS and ICP. The detection tool was developed using the android-based digital image method with SLR data analysis techniques obtained from the reaction of the metal ion complex Cr6 + with the compound dhypenilcarbazida (DPC). The parameters of the tool measured were accuracy, selectivity and sensitivity with the reaction of DPC compounds as complexes. The comparison level of this method is the complex method with DPC using a UV-Vis spectrophotometer. This research was carried out in the Chemistry Laboratory FKIP UNIB in November 2018 until March 2019. The implementation of tool parameters was tested to samples of aquatic environments in Bengkulu City, namely PDAM Kota Bengkulu water, tap water of FKIP UNIB Dean, Lake UNIB water, Sungai Hitam water and water Pantai Panjang. The results showed that the detection of Cr6+ metal ions made by the android-based digital image method had better accuracy, selectivity and sensitivity than conventional methods. The DPC is selective for Cr6 + metal ions with a change in color from clear to violet, at a wavelength of 540 nm. Accuracy was checked using a UV-Vis spectrophotometer with 99% accurate results. After that, test sensitivity to Cr6 + metal ions. using the android application method generates a Limit of Detection (LOD) of 6.7 ppb. The detector that was developed was applied to water samples in the city of Bengkulu, it turned out that all of the water samples showed that the levels of Cr6+ metal ions were still below the threshold determined by the Minister of Health Regulation, so it was still safe to use in everyday life.

scholarly journals Design and Development of Complexation of Ce+3 Metal Ions with Synthesized INZ Incorporated Bio-active Schiff Bases

2021 ◽  
Vol 11 (4) ◽  
pp. 3989-4006
Keyword(s):  
Schiff Base ◽  
Metal Ions ◽  
Schiff Bases ◽  
Elemental Analysis ◽  
Metal Ion ◽  
Organic Ligands ◽  
Schiff Base Complexes ◽  
Spectral Techniques ◽  
The Stability ◽  
Antibacterial And Antifungal

In the present research, a series of Ce+3 metal ions complexation with INZ incorporating Schiff bases have been reported. INZ incorporated Schiff Bases (3a-e) were developed by condensing INZ with substituted aromatic aldehyde and confirmed with various spectral Techniques such as Elemental analysis, UV, IR, 1H-NMR, 13H NMR. All the synthesized organic ligands were evaluated against antibacterial and antifungal stains and found moderate to significant results. The Ce+3 metal ion solution mixed with newly prepared bio-active INZ Schiff bases (3a-e) to afford the [Ce-INZ Schiff Base] complexes (4a-e). The stability constants of prepared complexes were evaluated and found in order as a (3e) > (3d) > (3a) > (3b) > (3c).

Research on Metal Ion Removal of Ceramic Printing Wastewater

2013 ◽  
Vol 664 ◽  
pp. 369-373 ◽  
Author(s):  
Ling Ling Shang ◽  
Ce Shi ◽  
Yong Li Zhang ◽  
Yong Min Liu
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Removal Rate ◽  
Iron Removal ◽  
Reaction Cell ◽  
Solution Ph ◽  
Flame Atomic Absorption ◽  
Removal Of Metal ◽  
Removal Of Metal Ions

The removal of the metal ions in the ceramic printing wastewater was influenced by using, stirring and precipitating of the solution pH, coagulant PAC, coagulant aid PAM and heavy metal scavenger. This experiment investigated the removal effect of the metal ions in the wastewater under different conditions. Flame atomic absorption spectrometry was adopted for the determination of the concentration of metal ions in the wastewater. The studies have shown that alkalization, PAC coagulation treatment have a role in the removal of metal ions in the ceramic printing wastewater. And the chromium and iron removal rate can reached 74.0% and 61.6% respectively. Heavy metal scavenger also have a better role in the removal of metal ions. And the chromium and iron removal rates were 82.3% and 76.2% respectively without dosing PAC. The number of reaction cell has no significant effect on the removal of metal ions.

scholarly journals A New Chelating Resin for Preconcentration and Determination of Mn(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II) by Flame Atomic Absorption Spectrometry

2003 ◽  
Vol 86 (6) ◽  
pp. 1218-1224 ◽  
Author(s):  
Mohan A Maheswari ◽  
Mandakolathur S Subramanian
Keyword(s):  
Metal Ions ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Flame Atomic Absorption Spectrometry ◽  
Water Samples ◽  
Metal Ion ◽  
Absorption Spectrometry ◽  
Metal Ion Extraction ◽  
Ion Extraction ◽  
Flame Atomic Absorption

Abstract A new polychelatogen, AXAD-16-1, 2-diphenylethanolamine, was developed by chemically modifying Amberlite XAD-16 with 1, 2-diphenyl-ethanolamine to produce an effective metal-chelating functionality for the preconcentration of Mn(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II) and their determination by flame atomic absorption spectrometry. Various physiochemical parameters that influence the quantitative preconcentration and recovery of metal were optimized by both static and dynamic techniques. The resin showed superior extraction efficiency with high-metal loading capacity values of 0.73, 0.80, 0.77, 0.87, 0.74, and 0.81 mmol/g for Mn(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II), respectively. The system also showed rapid metal-ion extraction and stripping, with complete saturation in the sorbent phase within 15 min for all the metal ions. The optimum condition for effective metal-ion extraction was found to be a neutral pH, which is a great advantage in the preconcentration of trace metal ions from natural water samples without any chemical pretreatment of the sample. The resin also demonstrated exclusive ion selectivity toward targeted metal ions by showing greater resistivity to various complexing species and more common metal ions during analyte concentration, which ultimately led to high preconcentration factors of 700 for Cu(II); 600 for Mn(II), Ni(II), and Zn(II); and 500 for Cd(II) and Pb(II), arising from a larger sample breakthrough volume. The lower limits of metal-ion detection were 7 ng/mL for Mn(II) and Ni(II); 5 ng/mL for Cu(II), Zn(II), and Cd(II), and 10 ng/mL for Pb(II). The developed resin was successful in preconcentrating metal ions from synthetic and real water samples, multivitamin-multimineral tablets, and curry leaves (Murraya koenigii) with relative standard deviations of <3.0% for all analytical measurements, which demonstrated its practical utility.

scholarly journals Comparative study of binding strengths of heavy metals with humic acid

2013 ◽  
Vol 67 (5) ◽  
pp. 773-779 ◽  
Author(s):  
Ivana Kostic ◽  
Tatjana Andjelkovic ◽  
Ruzica Nikolic ◽  
Tatjana Cvetkovic ◽  
Dusica Pavlovic ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Humic Acid ◽  
Metal Ions ◽  
Stability Constants ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Exchange Method ◽  
Divalent Metal Ion ◽  
The Stability

The complexation of humic acid with certain heavy metal ions (Co(II), Ni(II), Cu(II), Zn(II) and Pb(II)) was investigated. The stability constants of humate complexes were determined by method which is based on distribution of metal ions between solution and resin in the presence and the absence of ligand, known as Schubert?s ion exchange method. Experiments were performed at 25 ?C, at pH 4.0 and ionic strength of 0.01 mol dm-3. It was found that the 1:1 complexes were formed between metal ions and humic acid. Obtained results of the stability constants, log ?mn, of complexes formed between the metal ions and humic acid follow the order Co(II) < Ni(II) < Cu(II) > Zn(II) which is the same like in the Irving-Williams series for the binding strength of divalent metal ion complexes. Stability constant of complex between Pb(II) ions and humic acid is greater than stability constants of other investigated metal-humate complexes. The investigation of interaction between heavy metal ions and humics is important for the prediction of the distribution and control of the migration of heavy metals in natural environment.

scholarly journals Density Functional Theory Analysis of Poly Glycolic Acid with Metal Ions (Na+, K+) Interaction

2019 ◽  
Vol 9 (1S3) ◽  
pp. 366-369
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Density Functional ◽  
Glycolic Acid ◽  
Carbonyl Oxygen ◽  
Chemical Hardness ◽  
Binding Affinities ◽  
Functional Theory ◽  
Fukui Functions ◽  
The Stability

The complexation between Poly glycolic acid (PGA) and alkali metal ions (Na+ , K+ ) have been studied using B3LYP/6-311++G** method. The binding site of metal ion interaction on PGA is carbonyl oxygen. Both metal ions form bidendate complexation with PGA. Further, it can be noted that the PGA with K+ complex is more stable than the PGA with Na+ complex. The binding affinities (ΔH), basicity (ΔG) and the complexation entropies (ΔS) of all the studied systems are calculated. The interaction energy is maximum in PGA-Na+ than the PGA-K + complex. This is due to more charge transfer taking place between PGA and Na. The stability of the complex is studied by the chemical hardness value. The condensed Fukui functions are calculated and are used to predict the favourable reactive site

scholarly journals Diclofenac Sodium Determination in Pharmaceutical Preparations After Complexation With Calcium and Magnesium and Molecular Modelling Study.

2021 ◽  
Author(s):  
Waheed Ali Soomro ◽  
Muhammad Yar Khuhawar ◽  
Taj Muhammad Jahaangir ◽  
Muhammad Farooque Lanjwani ◽  
Rafi-u-Zaman Brohi ◽  
...  
Keyword(s):  
Metal Ions ◽  
Aqueous Phase ◽  
Metal Ion ◽  
Limit Of Detection ◽  
Diclofenac Sodium ◽  
Pharmaceutical Preparations ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Complexation Reactions

Abstract The study was carried out for indirect determination of diclofenac sodium in preparations after complexation with Ca or Mg. The diclofenac was treated with the metals individually and the metal complexes formed as precipitates were extracted in chloroform or separated by centrifugation. A decrease in concentration of metal ions was observed in aqueous phase which was correlated with concentration of diclofenac sodium. The complexation reactions were optimized in terms of pH, nature of metal ion, extraction in chloroform or separation by centrifugation. The decrease in concentration of metal ions in aqueous phase was monitored using flame Atomic Absorption Spectrophotometry (AAS) or by complexometric titration with EDTA. The linear calibration range observed were from 40-200 µg /mland 40-200 ug/mL diclofenac sodium respectively by using both Ca and Mg. The limit of detection was 15 µg /mL diclofenac using Ca or Mg ions using both solvent extraction and precipitation methods with AAS. The method was repeatable with interday and intraday reproducibility with relative standard deviation within 5%. The method was applied for the determination of diclofenac from pharmaceutical preparations, Voltral, Voren, Qufen, Dicloplus, Dicloran with RSD% 1.3%-8.2%.

scholarly journals N,N’-Bis(salicylidene)ethylenediamine (Salen) as an Active Compound for the Recovery of Ni(II), Cu(II), and Zn(II) Ions from Aqueous Solutions

Membranes ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 60
Author(s):  
Katarzyna Witt ◽  
Daria Bożejewicz ◽  
Małgorzata A. Kaczorowska
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Active Compound ◽  
Metal Ion ◽  
High Resolution Mass Spectrometry ◽  
Separation Of Metal Ions ◽  
Ion Separation ◽  
Liquid Liquid Extraction ◽  
The Stability ◽  
Complexes With Metal Ions

In this paper, three main methods of metal ion separation, i.e., liquid–liquid extraction, transport across polymer inclusion membranes (PIMs), and sorption/desorption, are described. In all of them, N,N’-bis(salicylidene)ethylenediamine (salen) was used as an active compound, i.e., as an extractant or as a carrier for the recovery of Ni(II), Cu(II), or Zn(II) ions from aqueous solutions. In each case, the recovery was performed on a model solution, which contained only a single metal ion. The obtained results were compared with the author’s previous results for the separation of metal ions using β-diketones, since both β-diketones and salen form the so-called Werner-type complexes. Electrospray ionization high-resolution mass spectrometry (ESI-HRMS) was also applied to confirm the ability of the carrier to form complexes with metal ions in a solution. Moreover, spectrophotometry was used to determine the stability constant of the obtained complexes.

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