scholarly journals Kinetics Study of Solvent and Solid-Phase Extraction of Rare Earth Metals with Di-2-Ethylhexylphosphoric Acid

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 687
Author(s):  
Olga Cheremisina ◽  
Vasiliy Sergeev ◽  
Maria Ponomareva ◽  
Alexandra Ilina ◽  
Alexander Fedorov
Keyword(s):  
Activation Energy ◽  
Solid Phase Extraction ◽  
Organic Phase ◽  
Solid Phase ◽  
Extraction Process ◽  
Separation Coefficient ◽  
Phase Extraction ◽  
Order Kinetic ◽  
Diffusion Limited ◽  
Limiting Stage

The kinetic features of solvent and solid-phase extraction of yttrium and iron (III) from simulated and industrial phosphoric acid solutions are revealed. Di-2-ethylhexylphosphoric acid (D2EHPA) was used as a liquid extractant, and D2EHPA-containing Levextrel resin—a co-polymerization product of styrene and divinylbenzene in the presence of D2EHPA—was used as a solid-phase extraction agent. Significant dependence of yttrium extraction rate constant on the stirring rate was revealed using the formal first-order kinetic equation. The data obtained characterizes a diffusion-limited process with an activation energy of 16.2 ± 1.3 kJ/mol. Temperature increase during the iron (III) extraction process leads to a changeover of a rate-limiting stage from kinetic to diffusion, accompanied by drop of activation energy from 40.0 ± 1.4 to 11.4 ± 1.2 kJ/mol. Effective separation of elements at the extraction stage is possible at temperatures of 283–300 K under non-equilibrium conditions of the ferric ions transport from aqueous to organic phase. This condition ensures a high yttrium–iron separation coefficient of 23.2 in 1.5–2 min. Extraction kinetics by Levextrel resin are described by Fick’s second law equation, which establishes the laws of diffusion in the solid grain of the organic phase with an activation energy of 18.5 ± 2.0 kJ/mol.

scholarly journals Determination of Phthalate Esters in Beverages and Water Samples by Solid Phase Extraction with Resin Based COFs as Filler

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3338
Author(s):  
Yunjie Ma ◽  
Xin Gao ◽  
Yang Ruan ◽  
Hang Cui ◽  
Li Zhang ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Phthalate Esters ◽  
Adsorption Behavior ◽  
Phthalate Ester ◽  
Phase Extraction ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Kinetic Adsorption

Resin based covalent organic framework material was used as filler for solid phase extraction (SPE), and the solid phase extraction effect was compared with that of traditional COF material (TpBD COFs). The enrichment capacity of four phthalate esters (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate) in beverage samples was investigated by SPE. Adsorption experiments showed that the kinetic adsorption behavior of COF materials for phthalate esters (PAEs) was more consistent with the quasi-second-order kinetic adsorption model, and the static adsorption behavior is more in line with the Freundlich isothermal adsorption model. Solid phase extraction experiments proved that the SPE column prepared with two COF materials as adsorbents had good adsorption effects, high recovery (water: 97.99–100.56% and beverage: 97.93–100.23%) and were reusable (50 cycles), which could meet the requirements for trace detection of phthalate ester. It was found that the solid phase extraction effect was better than the four types of commercial SPE columns. The new COF material reduced the cost of monomer use and provided the possibility for its industrial production. Meanwhile, it also provided a new feasible scheme for enriching trace phthalate esters in practical samples.

scholarly journals Evaluation of an Integrated Ultrafiltration/Solid Phase Extraction Process for Purification of Oligomeric Grape Seed Procyanidins

Membranes ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 147 ◽  
Author(s):  
Alba Gutierrez-Docio ◽  
Paula Almodóvar ◽  
Silvia Moreno-Fernandez ◽  
Jose Manuel Silvan ◽  
Adolfo J. Martinez-Rodriguez ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Water Flux ◽  
Grape Seed Extract ◽  
Grape Seed ◽  
Extraction Process ◽  
Seed Extract ◽  
Transmembrane Pressure ◽  
Phase Extraction ◽  
Chemical Cleaning

The effectiveness of a preparative integrated ultrafiltration/solid-phase extraction (UF/SPE) process for purification of oligomeric procyanidins (OPCs) from a crude grape seed extract (GSE) was studied for the first time. The separation of OPCs from polymeric procyanidins (PPCs) by UF was very efficient. The membrane showed an acceptable filtration flux of 6 to 3.5 L/h·m2 at 0.5 bar of transmembrane pressure and 95% recovery of its water flux after chemical cleaning. The process was scalable to a pilot scale. The separation of very polar and ionic species from OPCs by SPE (XAD7HP and XAD16 resins) was also very good, but both adsorbents lost their retention capacities quickly, due probably to irreversible retention of OPCs/PPCs. Even though the global purification of OPCs by the integrated UF/SPE process allowed the recovery of 24.2 g of highly purified OPCs (83% purity) from 14.4 L of crude grape seed extract, the use of these adsorbents for further purification of the OPCs was very limited.

Extraction and Determination of RDX and HMX in Water

1999 ◽  
Vol 34 (3) ◽  
pp. 533-544 ◽  
Author(s):  
Eny M. Vieira ◽  
Francis I. Onuska
Keyword(s):  
Sodium Chloride ◽  
Solid Phase Extraction ◽  
Ammonium Sulfate ◽  
Organic Phase ◽  
Lake Water ◽  
Energetic Materials ◽  
Solid Phase ◽  
Phase Extraction ◽  
Salting Out

Abstract The analysis of energetic materials such as RDX and HMX in water at trace levels was accomplished by using micro-extraction by miscible solvents, such as acetonitrile, 2-propanol and acetone, and salting out the organic phase. This paper compares the results obtained with solid-phase extraction (SPE) to those obtained by demixing techniques for spiked Milli-Q water and an unfiltered lake water. A review of the data indicates that demixing with acetonitrile-sodium chloride and 2-propanol ammonium sulfate gives better extraction recoveries than solid-phase extraction. Salting-out extractions are performed in less time and with less solvent than by SPE techniques.

scholarly journals Behavior evaluation of freundlich and langmuir isotherms in cadmium preconcentration using solid phase extraction method for linear and nonlinear numerical computational patterns

2021 ◽  
Vol 5 (1) ◽  
pp. 007-010
Author(s):  
Chahkandi Benyamin ◽  
Gheibi Mohammad ◽  
Takhtravan Amir
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Freundlich Isotherm ◽  
Extraction Process ◽  
Linearization Method ◽  
Phase Extraction ◽  
Langmuir Adsorption ◽  
Adsorption Processes ◽  
Constant Coefficients ◽  
Epidemiological Effects

Cadmium is naturally present in the mineral cadmium sulfide which is a rare form of this element and the highest amount of cadmium is obtained from the extraction process of other minerals such as lead, copper and zinc. The release of this metal into the environment leads to widespread epidemiological effects. Therefore, measuring small amounts of this metal is also of particular importance. Small amount measuring methods of this metal are such as,preconcentration using solid phase extraction system using adsorbents. The main part of the preconcentration process is achieved by adsorption processes. In this study, the behavior of Freundlich and Langmuir adsorption isotherms for the capacity of TMON and IMNM adsorbents in cadmium adsorption has been evaluated by Power and Rational statistical distributions. At the end of the study, the constant coefficients of the Freundlich and Langmuir models were compared in both linear and non-linear modes. The results showed; the linearization method for the Kf coefficient of the Freundlich isotherm can cause errors equal to 41.6% in TMON adsorbent and 39.3% in IMNM adsorbent. Also, in parameter b, errors of 66.66% are obtained in TMON adsorbent and 32.45% in IMNM adsorbent.

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