Extraction of Zn(II), Cd(II), and Hg(II) by dodecyloligo(oxyethylene) carboxylic acids

1988 ◽  
Vol 66 (7) ◽  
pp. 1695-1700 ◽  
Author(s):  
Jerzy Strzelbicki ◽  
Witold Charewicz ◽  
Jorg Beger ◽  
Lutz Hinz
Keyword(s):  
Molecular Structure ◽  
Carboxylic Acids ◽  
Aqueous Phase ◽  
Metal Cation ◽  
High Selectivity ◽  
Extraction Process ◽  
Experimental Conditions ◽  
Chemical Equilibria ◽  
Complex Chemical ◽  
Solution Parameters

The synthesis of a series of n-dodecyloligo(oxyethylene) carboxylic acids of general formula C12H25(OCH2CH2)nOCH2COOH (n = 0 to 5) and application of these compounds for the separation of Zn(II), Cd(II), and Hg(II) in extraction are reported. Negligible extractability of the metal ions investigated was found using dodecyloxyacetic acid (n = 0) which indicated that complexation resulted from metal–cation interaction with oxygen atoms of the polyoxyethylene chain incorporated into the molecule of complexon. In extractions from aqueous solutions containing ZnCl2, CdCl2, HgCl2, and NaOH (pH regulator), loading of the organic phases increased for extractants with more oxyethylene units. In particular, Hg(II) extractability and molecular structure of the extractant are related. The selectivity of extraction increased drastically if NaCl was added to the initial aqueous phase, as the extractabilities of Cd(II) and, particularly, Hg(II) declined while the extractability of Zn(II) remained high. Selectivity of extraction is produced by the complex chemical equilibria resulted from complexation of the metal cation by an alkyloligoether carboxylic acid in the organic phase and by Cl− and OH− anions in the aqueous phase. Thus, aqueous solution parameters greatly influence the efficiency and the selectivity of the extraction process and suitable experimental conditions are very important.

scholarly journals Label-Free Electrochemical Test of Protease Interaction with a Peptide Substrate Modified Gold Electrode

Chemosensors ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 199
Author(s):  
Anna Wcisło ◽  
Izabela Małuch ◽  
Paweł Niedziałkowski ◽  
Tadeusz Ossowski ◽  
Adam Prahl
Keyword(s):  
Gold Electrode ◽  
High Selectivity ◽  
Electrode Materials ◽  
Electrochemical Biosensors ◽  
Electrochemical Characteristics ◽  
Label Free ◽  
Peptide Substrate ◽  
Electrochemical Test ◽  
Experimental Conditions ◽  
Spectrofluorimetric Method

Efficient deposition of biomolecules on the surface, maintaining their full activity and stability, is a most significant factor in biosensor construction. For this reason, more and more research is focused on the development of electrochemical biosensors that have the ability to electrically detect adsorbed molecules on electrode surface with high selectivity and sensitivity. The presented research aims to develop an efficient methodology that allows quantification of processes related to the evaluation of enzyme activity (proprotein convertase) using electrochemical methods. In this study we used impedance spectroscopy to investigate the immobilization of peptide substrate (Arg-Val-Arg-Arg) modified with 11-mercaptoundecanoic acid on the surface of gold electrode. Both the synthesis of the peptide substrate as well as the full electrochemical characteristics of the obtained electrode materials have been described. Experimental conditions, including concentration of peptide substrate immobilization, modification time, linker, and the presence of additional blocking groups have been optimized. The main advantages of the described method is that it makes it possible to observe the peptide substrate–enzyme interaction without the need to use fluorescent labels. This also allows observation of this interaction at a very low concentration. Both of these factors make this new technique competitive with the standard spectrofluorimetric method.

scholarly journals Optimization of Microwave-Assisted Extraction of Phlorotannin From Sargassum swartzii (Turn.) C. Ag. With Ethanol/Water

2021 ◽  
Vol 16 (2) ◽  
pp. 1934578X2199618
Author(s):  
Tran Quoc Toan ◽  
Tran Duy Phong ◽  
Dam Duc Tien ◽  
Nguyen Manh Linh ◽  
Nguyen Thi Mai Anh ◽  
...  
Keyword(s):  
Output Power ◽  
Ethanol Concentration ◽  
Biological Activities ◽  
Solvent System ◽  
Extraction Process ◽  
Extraction Time ◽  
Brown Macroalgae ◽  
Experimental Conditions ◽  
Total Extract ◽  
Sargassum Swartzii

Sargassum is a genus of brown macroalgae in the class Phaeophyta, distributed widely in all oceans, including those of Vietnam. Species of this genus have been proven to possess diverse biological activities, such as antioxidant, anti-fungal, and anti-inflammatory, along with many benefits and applications for human health, including anti-diabetic, obesity, and thrombosis. These benefits arise from a diverse chemical composition, with compounds such as fucoidan, mannitol, and especially phlorotannin—a group of phenolic derivatives found predominantly in brown algae. In this study, we evaluated and optimized the factors that affected the extraction process of phlorotannins from Sargassum swartzii (Turn.) C. Ag., a common species of brown macroalgae in Vietnam. The process utilized ethanol and water as the solvent system, and the extraction process was assisted with the use of microwaves. To carry out optimization studies, Response Surface Methodology (RSM) was adopted according to a Central Composite Desisgn (CCD), taking four processing factors into consideration, ethanol concentration (%, v/v), extraction time (minutes), solvent/material ratio (v/w), and microwave output power (W) as independent variables. Phlorotannin concentration (mgPhE/g) and extract mass (mg) were regarded as optimization outcomes. Experimental conditions that produced the highest phlorotannin yield from 10 g of S. swartzii are as follows: Extraction time of 65 minutes, ethanol concentration of 52%, microwave output power of 613 W, and solvent/material ratio of 33/1 (v/w). These conditions corresponded to a phlorotannin concentration of 5.59 ± 0.11 mg PhE/g, and a total extract content of 27.88 ± 0.13 mg/g.

scholarly journals Another Way to Solve Complex Chemical Equilibria

1990 ◽  
Vol 38 (2) ◽  
pp. 355-358 ◽  
Author(s):  
Daniel P. Heyman
Keyword(s):  
Chemical Equilibria ◽  
Complex Chemical

scholarly journals OR Practice—Solving Complex Chemical Equilibria Using a Geometric-Programming Based Technique

1986 ◽  
Vol 34 (3) ◽  
pp. 345-355 ◽  
Author(s):  
Thomas Wayne Wall ◽  
Doran Greening ◽  
R. E. D. Woolsey
Keyword(s):  
Geometric Programming ◽  
Chemical Equilibria ◽  
Complex Chemical ◽  
Or Practice

scholarly journals Reverse Micelle Liquid-Liquid Extraction of a Pharmaceutical Product

2012 ◽  
Vol 545 ◽  
pp. 240-244 ◽  
Author(s):  
Siti Hamidah Mohd-Setapar ◽  
Siti Norazimah Mohamad-Aziz ◽  
N.H. Harun ◽  
S.H. Hussin
Keyword(s):  
Aqueous Solution ◽  
Aqueous Phase ◽  
Reverse Micelle ◽  
Surfactant Concentration ◽  
Protein Extraction ◽  
Biological Activities ◽  
Extraction Process ◽  
Pharmaceutical Product ◽  
Penicillin G ◽  
Reverse Micelle Extraction

Reverse micelle extraction has received considerable attention in recent years due to its ability to selectively solubilise solutes from an aqueous phase, and in the case of biomolecules to maintain their biological activities. The apparent success of research on protein extraction from the aqueous phase using reverse micelle provides motivation to study the solubilisation of antibiotic. The objective of this study is to investigate the extraction of antibiotic (penicillin G is chosen as model antibiotic) from aqueous solution (forward extraction) and from the reverse micelle to a new aqueous solution (backward extraction). Sodium di(2-ethylhexyl)sulfosuccinate (AOT) is chosen as the surfactant and isooctane as the organic solvent. The UV-Vis spectrophotometer is used to determine the mass of penicillin G in solution after the extraction process. The extraction is expected to be influenced by the initial penicillin G concentration, the salt type and concentration in the aqueous phase, pH, and surfactant concentration. It is expected that as penicillin is an interfacially active compound that will interacts with AOT surfactant, the interfacial association will be dependent on both pH and surfactant concentration.

scholarly journals New extraction techniques on bioseparations: 2. Pertraction, direct extraction

2004 ◽  
Vol 58 (12) ◽  
pp. 535-547
Author(s):  
Anca-Irina Galaction ◽  
Dan Cascaval
Keyword(s):  
Mathematical Models ◽  
Carboxylic Acids ◽  
Separation Efficiency ◽  
Extraction Techniques ◽  
Direct Extraction ◽  
Experimental Conditions ◽  
Maximum Separation

The second part of this review presents our original results on the separation of some biosynthetic products (antibiotics, carboxylic acids, alcohols) by pertraction and direct extraction from broths without biomass filtration. For the analyzed systems, the experimental conditions required for reaching maximum separation efficiency and the mathematical models describing the process have been established. For all the studied cases, these extraction techniques simplify the technologies and reduce the overall cost of the product.

Electron transfer between ferrocene and hexacyanoferrate(III) across the water/1,2-dichloroethane interface

1988 ◽  
Vol 53 (5) ◽  
pp. 903-911 ◽  
Author(s):  
Josef Hanzlík ◽  
Jan Hovorka ◽  
Zdeněk Samec ◽  
Štefan Toma
Keyword(s):  
Electron Transfer ◽  
Aqueous Phase ◽  
Rate Constant ◽  
Potential Range ◽  
Ion Transfer ◽  
Potential Sweep ◽  
Experimental Conditions ◽  
Chemical Decomposition ◽  
Kinetics Of

Kinetics of electron transfer between ferrocene or its derivative (1,1'-diethyl- or 1,1'-distearoylferrocene) in dichloroethane and hexacyanoferrate(III) in water was studied by means of convolution potential sweep voltammetry. Within the accessible range of experimental conditions no effect of either the potential or concentrations of reactants on the rate constant of electron transfer from the organic to the aqueous phase (ko→w = 1 . 10-7 m4 mol-1 s-1) was observed. Electron transfer was shown to occur far from the potential range, in which the ferricenium ion transfer can take place. However, the reaction was complicated by the chemical decomposition of ferricenium in dichloroethane (k = 0·346 s-1).

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