N-butyl Phosphate Research Articles

Inside-Out Oriented Choline Phosphate-Based Biomimetic Magnetic Nanomaterials for Precise Recognition and Analysis of C-Reactive Protein.

Phospholipid-based materials exhibit great application potential in the fields of chemistry, biology, and pharmaceutical sciences. In this study, an inside-out oriented choline phosphate molecule, 2-{2-(methacryloyloxy)ethyldimethylammonium}ethyl n-butyl phosphate (MBP), was proposed and verified as a novel ligand of C-reactive protein (CRP) to enrich the functionality of these materials. Compared with phosphorylcholine (PC)-CRP interactions, the binding between MBP and CRP was not affected by the reverse position of phosphate and choline groups and even found more abundant binding sites. Thus, high-density MBP-grafted biomimetic magnetic nanomaterials (MBP-MNPs) were fabricated by reversible addition-fragmentation chain transfer polymerization based on thiol-ene click chemistry. The novel materials exhibited multifunctional applications for CRP including purification and ultrasensitive detection. On the one hand, higher specificity, recovery (90%), purity (95%), and static binding capacity (198.14 mg/g) for CRP were achieved on the novel materials in comparison with traditional PC-based materials, and the enriched CRP from patient serum can maintain its structural integrity and bioactivity. On the other hand, the CRP detection method combining G-quadruplex and thioflavin T developed with MBP-MNPs showed a lower detection limit (10 pM) and wider linear range (0.1-50 nM) than most PC-functionalized analytical platforms. Therefore, the inside-out oriented choline phosphate can not only precisely recognize CRP but also be combined with biomimetic nanomaterials to provide high application potential.

Removal of Mercury in Aqueous Solutions Using Tri n-Butyl Phosphate-Based Polymer Inclusion Membrane

Polymer inclusion membranes (PIM) have gained global attention in the removal of heavy metals from aqueous samples. Mercury is a toxic metal that can cause serious health effects to humans even if present in traces. Hence, its removal from water bodies and wastewaters is a necessary action. The present work, thus, aims at studying the removal of Hg2+ ions by using PIM with a new and unexplored neutral carrier, namely, Tri n-butyl phosphate and Dioctyl phthalate as a plasticizer. One hundred percent removal was attained for feed phase mercury concentrations from 0.01 to 2 mg/L and about 96% for 10 mg/L under optimum conditions (thickness of the membrane: 30 μm, feed phase acid: 0.3 M, strip phase alkali: 0.4 M, carrier: 3% and stirring speed: 400 rpm). The PIM system has been successfully demonstrated to remove trace concentrations of mercury in spiked seawater, thermal powerplant wastewater discharge, and contaminated lake water samples. The PIM was highly stable (60 h) and selective for Hg2+ ions. Also, the most significant factor in the transport of mercury through the PIM was determined as the feed phase mercury concentration using the Taguchi method. Thus, the proposed PIM system could be used for the selective removal of mercury ions from water and wastewater samples.

Removal of Hg2+ ions using tri n-butyl phosphate based supported liquid membrane from aqueous samples

Mercury is a poisonous heavy metal that causes deleterious effects on public health and the ecosystem, even with a trace level of contamination. Selective separation of mercury ions in an aqueous environment is a challenging task, while supported liquid membrane poses to be a promising tool. In this research work, the removal of mercury ions using a porous PTFE membrane with TBP as a carrier has been studied. Batch experiments were carried out in an SLM reactor with feed phase and strip phase solution on either side of the membrane. Maximum removal of 97% of Hg2+ ions occurred under optimum conditions, namely, 0.5 M of HCl (feed), 0.4 M NaOH (strip), 90% of TBP, stirring speed at 300 rpm and 3 h of reaction time. SEM analysis of the membrane confirmed the formation of a complex between TBP and Hg2+ ions. SLM was found to be stable for 18 h. The high selectivity of the SLM towards Hg2+ ions was unaltered in the presence of Cd2+, Ni2+ and Zn2+ ions. The proposed SLM was used for the treatment of spiked seawater samples, wastewater from a thermal power plant, and contaminated lake water samples. The results indicated that the SLM system was highly efficient in removing Hg2+ ions from real contaminated samples.

Removal of mercury(II) by tri n-butyl phosphate based supported liquid membrane

ABSTRACT. Mercury even at a trace level poses a significant threat to the environment and the ecosystem. Thus, prompting the need to develop a technology to separate mercury(II) selectively from aqueous solutions. The removal of mercury(II) from aqueous solutions using tri n-butyl phosphate (TBP) based supported liquid membrane (SLM) was investigated in this study. HCl and NaOH were used as feed and strip phases, respectively. Factors considered for designing the experiments using the Taguchi method include feed phase acid concentration, strip phase alkali concentration, carrier concentration and initial feed phase mercury(II) concentration. The results indicated that carrier concentration was the most influential factor on the removal efficiency. The percentage contribution of each factor was calculated. The results show that carrier concentration and initial feed phase mercury(II) concentration have a maximum contribution. For the maximum removal of 91.7% of mercury(II) (initial concentration - 10 mg/L) in the feed phase, the optimum conditions were 0.3 M of HCl, 0.2 M of NaOH, and 90% of TBP. SEM analysis was performed to evidence the transportation process through the membrane. The research study indicated the potential use of TBP as a carrier in the SLM system for the selective separation of mercury in trace concentration.
 
 KEY WORDS: Removal of mercury(II), Tri n-butyl phosphate, Taguchi method, Supported liquid membrane
 
 Bull. Chem. Soc. Ethiop. 2021, 35(2), 273-286.
 DOI: https://dx.doi.org/10.4314/bcse.v35i2.5

A simple microanalytical method for trace elemental determination in plutonium samples using energy dispersive X-ray fluorescence

A simple microanalytical method for trace elemental determinations in plutonium (Pu) solution samples was developed using Energy Dispersive X- Ray Fluorescence (EDXRF) spectrometry. A very small sample volume (200 μL) of Pu solution was taken for analysis and the major matrix Pu was separated using the extractant, Tri n-Butyl Phosphate (TBP), in 4 M HNO3 medium. Aliquot of 5 μL of the aqueous phase containing only the trace elements were deposited on a thin transparent mylar film inside the PVC (Poly Vinyl Chloride) EDXRF sample container and dried in ambient atmosphere inside a radioactive fume hood. After drying, the container was sealed with PVC lids. Two pure Pu solutions spiked with different trace elements having concentration of 6.25 and 23.25 μg/mL, were analyzed with RSD (Relative Standard Deviation) of 6.6 and 4.2% (1 σ, n = 3), and the average deviation from the expected values calculated on the basis of sample preparation were 8.9 and 6.6%, respectively. The developed methodology requires small amount of sample, extractant, and therefore generates less radioanalytical waste. Moreover, due to the requirement of small amount of sample, sealed inside a PVC container, the measurements could be carried out in ambient atmosphere without putting the instrument inside glove box. Further, the simple instrumentation of EDXRF, made this methodology very much ideal for the routine analysis of plutonium based samples.

Numerical Simulation of Uranium Extraction from Nitric Acid Medium Using Hollow-Fiber Contactor

ABSTRACTA two-dimensional axisymmetric computational fluid dynamics (CFD) model is presented to simulate uranium extraction from nitric acid medium using tri-n-butyl phosphate in n-dodecane in a hollow-fiber membrane contactor operated in non-dispersive solvent extraction mode. CFD model solves continuity and momentum-transport equations for the feed and shell sides and species transport equations for the feed side, shell side, as well as the membrane. Complex boundary conditions of flux continuity and concentration jump are implemented in the CFD model. The estimates of percentage of uranium extraction obtained from CFD simulations for different parametric conditions are compared with the experimental results, and a good agreement is observed. The validated CFD model is used to gain detailed insights into the hydrodynamics and mass transfer.Abbreviations CFD: Computational fluid dynamics; NDSX: Non-dispersive solvent extraction; TBP: Tri n-butyl phosphate

Microscopic Behaviors of Tri- n-Butyl Phosphate, n-Dodecane, and Their Mixtures at Air/Liquid and Liquid/Liquid Interfaces: An AMBER Polarizable Force Field Study.

In solvent extraction processes for recovering metal ions from used nuclear fuel, as well as other industrial applications, a better understanding of the metal complex phase transfer phenomenon would greatly aid ligand design and process optimization. We have approached this challenge by utilizing the classical molecular dynamics simulations technique to gain visual appreciation of the vapor/liquid and liquid/liquid interface between tri- n-butyl phosphate (TBP) and n-dodecane with air and water. In this study, we successfully reparameterized polarizable force fields for TBP and n-dodecane that accurately reproduced several of their thermophysical properties such as density, heat of vaporization, and dipole moment. Our models were able to predict the surface and interfacial tension of different systems when compared to experimental results that were also performed by us. Through this study, we gained atomistic understanding of the behaviors of TBP and n-dodecane at the interface against air and water, useful in further computational studies of such systems. Finally, our studies indicate that the initial configuration of a simulation may have a large effect on the final result.

Influence of Branching on the Conformational Space: Case Study of Tri- sec-butyl Phosphate Using Matrix Isolation Infrared Spectroscopy and DFT Computations.

The conformational analysis of long chain phosphates poses a serious challenge due to the presence of rotationally flexible multiple alkyl groups. Tri- sec-butyl phosphate (TsBP) is an interesting example, in which branching can be expected to influence the conformational landscape. To solve the conformational problem of TsBP systematically, the conformations of model dimethyl- sec-butyl phosphate (DMsBP), a molecule possessing a single secondary butyl strand, were analyzed. On the basis of the analysis of the energy profile of DMsBP, a few conformational bunches were eliminated. The presence of branched methyl group appears to completely influence the conformational space of TsBP and as a result, the number of conformations is drastically reduced in comparison to its structural isomer, tri- n-butyl phosphate (TBP). B3LYP level of theory in association with 6-311++G(d,p) basis set was used for computing all the conformer geometries. Experimentally, the conformations of TsBP were studied using infrared spectroscopy by trapping the molecule in N2 and Ar matrixes at low temperatures, which were correlated well with the computational results.

Hydrophilic polymeric monoliths containing choline phosphate for separation science applications

In this research, a hydrophilic polymeric monolith containing choline phosphate (CP) was fabricated through the thermally initiated free-radical polymerization of 2-{2-(methacryloyloxy) ethyldimethylammonium}ethyl n-butyl phosphate (MBP) with ethylene dimethacrylate (EDMA) using isopropanol and tetrahydrofuran as the porogenic system. Excellent mechanical strength, permeability, stability and reproducibility were obtained on the optimized poly(MBP-co-EDMA) monolith. Column efficiency as high as 107,500 plates/m was achieved for the analysis of thiourea at a flow velocity of 0.2 mm/s on the monolith. Both hydrophilic and electrostatic interactions were observed for the retention of charged analytes on the poly(MBP-co-EDMA) monolith. It is worth noting that the resulting monolith exhibits higher selectivity and efficiency than the classical 2-(methacryloyloxy)ethyl phosphorylcholine functionalized polymeric monolith for the chromatographic separation of polar analytes. Also, the novel monolithic column was successfully applied to enrich N-glycopeptides from tryptic digest of human IgG. In a word, the versatile MBP functionalized polymeric monolith not only opens up interesting possibilities for reverse zwitterionic CP derivative-based polymeric materials in separation science, but also represents a promising hydrophilic interaction chromatography stationary phase.

Thermal decomposition behaviour of irradiated tri n-butyl phosphate and mixture of di and mono n-butyl phosphate-nitric acid systems

Tri-n-butyl phosphate (TBP) is employed in nuclear reprocessing plants. During the evaporation process, formation of red oil, an unstable compound can cause runaway reaction. In this context, thermal decomposition of TBP-HNO3 and TBP-n-dodecane has been studied as a function of HNO3 concentration using adiabatic calorimeter. Effect of radiolysis on thermal decomposition of TBP has been investigated for the first time. Neat TBP is stable up to 527±1K and the irradiated TBP is up to 513±1K. Thermal decomposition of degradation products of TBP namely, dibutyl and monobutyl phosphates have also been investigated for the first time. Thermo-kinetic parameters e.g. enthalpy of decomposition, activation energy, pre-exponential factor and order of reaction were computed. Enthalpies of decomposition for TBP–4M HNO3 vary from 64 to 495kJmol−1 whereas that of TBP–8M HNO3, 368–1187kJmol−1. TBP-HNO3 on thermal decomposition produces CO, CO2, NOx, hydrocarbons and highly viscous black liquid.

The influence of phosphorus precursor on the structure and properties of SiO2–P2O5–CaO bioactive glass

Bioactive glasses (BGs) are one of the most promising bone regeneration materials because they can bond to bone and simulate new bone growth. Sol–gel methods for producing BG are well established, however challenges still remain in selecting and optimizing the precursors. Even for BGs with the same final composition, different precursors may lead to different structures and properties of the gel derived BG. In this work, three different phosphorus precursors, phytic acid (PA), triethyl phosphate (TEP) and n-butyl phosphate (BP) were used to prepare BG (54.2%SiO2–35%CaO–10.8%P2O5, mol%). The obtained materials were characterized by TGA, FTIR, XRD, HEXRD, solid state 31P, 29Si NMR and by in vitro tests in SBF. It was found that the materials prepared by TEP or BP showed small amounts of crystallization, whereas the resulting material prepared by PA remained amorphous and had more P atoms as orthophosphate. In vitro assays indicated that all these materials were bioactive, while the BG prepared by PA showed the highest in vitro bioactivity, followed by TEP and, finally, BP. Based on these observations, it appears that phosphorus precursors have a significant impact on both the structure and bioactivity of the sol–gel derived BG. Results suggest that PA should be used in preference to TEP or n-butyl phosphate for the synthesis of sol gels. PA may improve the homogeneity of the sol gel glasses, reduce crystallization and lower stabilization temperatures.

Evaluation of hydrodynamic suitability of N,N-didodecyl N′,N′-di-octyl diglycolamide: a potential candidate for minor actinide partitioning

An unsymmetrical diglycolamide namely N,N, didodecyl-N′,N′-dioctyl diglycolamide developed in our laboratory is evaluated for its hydrodynamic suitability by determining the changes in its physical properties such as density and viscosity as a function of temperature and compared with those of tri n-butyl phosphate and N,N,N′,N′-tetraoctyl diglycolamide. The effect of irradiation on density, viscosity and interfacial tension, up to a dose of 1000 kGy are also measured. In addition, the activation energy for the viscous flow (E vis) were obtained for these pure solvents and their binary mixtures with n-dodecane in the temperature range 20–65 °C using the Andrade’s equation.

Comparative studies on co-extraction of uranium(VI) and different mineral acid from aqueous feed solutions using TBP, TOPO and TOA

Equilibrium and kinetics of co-extraction of hexavalent uranium and mineral acids from aqueous solutions into a hydrocarbon phase (paraffin) using tri n-butyl phosphate (TBP), tri-n-octyl phosphine oxide (TOPO) and tri-n-octyl amine (TOA) has been studied. Relative rates of extraction of uranium(VI) and mineral acid by different complexing ligands were measured simultaneously using bulk-liquid membrane system. Acid extraction by complexing ligands was found to be significant. Wherever there was a possibility of the formation of the third phase, isodecanol was used as an organic phase modifier. Study revealed that isodecanol promotes acid extraction and substantially reduces distribution coefficient of U(VI) into the hydrocarbon phase. The rate of acid extraction by different ligand was in the order of TOPO > TOA > TBP–isodecanol > TBP, whereas the rate of extraction of uranium(VI) was in the order TOPO > TOA > TBP > TBP–isodecanol. A kinetic model was developed to predict concentration of acid and U(VI) in the feed, organic and the strip phase during extraction. The mass transfer coefficients for acid and metal were determined by fitting the model to the observed concentration–time data.

Thermal decomposition characteristics of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide-tri n-butyl phosphate–nitric acid systems

Thermal stability of neat octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (OΦD[IB]CMPO) and TRUEX solvent composition (0.2M OΦD[IB]CMPO-1.2M tri n-butyl phosphate-in n-dodecane) in the presence and absence of nitric acid has been studied in ambient air in a closed vessel, employing an adiabatic calorimeter. Enthalpies and kinetic parameters for the decomposition reaction were derived wherever possible and are reported for the first time. Neat OΦD[IB]CMPO was found to be thermally stable up to 633 K and exhibited an exothermic decomposition later. It decomposed at lower temperatures (376–386 K) depending on the nitric acid concentration. The exothermic rise in temperature and pressure increased exponentially, while activation energies exhibited exponential decrease for the decomposition reactions with increase in nitric acid content. TRUEX solvent was found to be stable up to 661 K in the absence of nitric acid while in the presence of 8 and 4M HNO3, it decomposed between 387 and 413 K. All these samples on decomposition formed incompressible gases and viscous black liquids. The results also indicate that the neat OΦD[IB]CMPO and the TRUEX solvent are thermally more stable than neat tri n-butyl phosphate (TBP), PUREX solvent (1.1M TBP/n-DD), neat diamyl amyl phosphonate (DAAP) and 1.1M DAAP/n-DD, triisoamyl phosphate (TiAP) and 1.1M TiAP/n-DD.

Characterization of the Species Formed during the Extraction of Thorium Employing Tri-n-Butyl Phosphate and N,N-Dihexyl Octanamide as Extractants by Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Laser desorption/ionization-time-of-flight mass spectrometry (LDI-ToF-MS) has been applied to identify and characterize the organic phase species formed during the extraction of thorium nitrate by 1.1 M tri-n-butyl phosphate (TBP) and N,N-dihexyl octanamide (DHOA) solutions in n-dodecane. The aqueous phase thorium concentrations (at 4M HNO3) have been suitably chosen to get Loaded organic phases with/without third-phase. The extracted species have been characterized for the first time using LDI-ToF-MS. The results show feasibility of the use of this technique for understanding the extraction mechanisms and third-phase formation behavior of different extractants. The different chemical species observed using this technique are consistent with those observed by small-angle neutron scattering (SANS).

Aggregate structures of asymmetric di-alkylphosphate anions in concentrated aqueous solutions and the role of the short chain: X-ray diffraction and Raman scattering studies

The microstructures of concentrated aqueous solutions of n-butyl(n-dodecyl)phosphate (BDoP) and n-hexyl(n-dodecyl)phosphate (HDoP) anions, as asymmetric double-chain surfactants, were studied using X-ray diffraction and Raman scattering techniques. The results indicated a marked difference in the aggregate behavior between BDoP and HDoP, attributed to the difference in the extent of the steric effect of the two short chains. The Raman scattering spectra provided direct evidence of the steric effect. This marked difference in the steric effect is clearly reflected in the phase structures of the BDoP and HDoP water binary systems.

Development of Alternate Extractants for Separation of Actinides

Selection of an extractant plays a key role in the development of a commercial solvent extraction process. Though tri- n-butyl phosphate (TBP) is currently used as the extractant for the processing of fast reactor fuel, there is a need to introduce an alternate extractant to ensure the success of closing the fast reactor fuel cycle in India. Recent studies undertaken in our laboratory for the identification of the most suitable extractant for fast reactor fuel reprocessing are addressed in this paper. Studies carried out on the influence of alkoxy groups of dialkylalkyl phosphonates on the extraction behaviour of uranium and thorium is also discussed.

Spectrophotometric determination of dissolved tri n-butyl phosphate in aqueous streams of Purex process

A spectrophotometric method is developed for the determination of dissolved tri-n butyl phosphate (TBP) in aqueous streams of Purex process used in nuclear fuel reprocessing. The method is based on the formation of phosphomolybdate with added ammonium molybdate followed by reduction with hydrazine sulphate in acid medium. Orthophosphate and molybdate ions combine in acidic solution to give molybdophosphoric (phosphomolybdic) acid, which upon selective reduction (with hydrazinium sulphate) produces a blue colour, due to molybdenum blue. The intensity of blue colour is proportional to the amount of phosphate. If the acidity at the time of reduction is 0.5 M in sulphuric acid and hydrazinium sulphate is the reductant, the resulting blue complex exhibits maximum absorption at 810–840 nm. The system obeys Lambert–Beer’s law at 830 nm in the concentration range of 0.1–1.0 μg/ml of phosphate. Molar Absorptivity was determined to be 3.1 × 104 L mol−1 cm−1 at 830 nm. The results obtained are reproducible with standard deviation of 1 % and relative error less than 2 % and are in good agreement with those obtained by ion chromatographic technique.

Removal of dissolved Tri n-butyl phosphate from aqueous streams of reprocessing origin: engineering scale studies

Removal of dissolved Tri n-butyl phosphate from aqueous streams of reprocessing origin: engineering scale studies

A solvent extraction process with mixture of CA12 and Cyanex272 for the preparation of high purity yttrium oxide from rare earth ores

Solvent extraction and separation of yttrium from other rare earths in chloride medium using the mixture of sec-octylphenoxy acetic acid (CA12, HA) and bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex272, HB) has been investigated. Tri- n-butyl phosphate (TBP) was used as the phase modifier to achieve fast phase separation and to improve the stability of the organic phase. The separation coefficients (β) between yttrium and heavy rare earths (HRE) are more significant in the double solvent (HAB) extraction system than the CA12-TBP extraction system. In a laboratory scale test with a fractional extraction process including 15 stages of extraction section and 10 stages of scrubbing section, yttrium was separated from all the other rare earths with a yield of 95% and an yttrium oxide product with 99.94% purity was obtained.