N-butyl Phosphate Research Articles

Antimicrobial effects of a microemulsion and a nanoemulsion on enteric and other pathogens and biofilms

Some microemulsions and nanoemulsions may have antimicrobial properties and be effective anti-biofilm agents. We examined the abilities of two fine emulsions, designated BCTP and TEOP, to inactivate suspensions of vegetative cells of Salmonella spp. Escherichia coli 0157:H7 (VT-), Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. BCTP is an O/W nanoemulsion of soybean oil and tri- n-butyl phosphate emulsified with Triton X-100, while TEOP is an O/W microemulsion of ethyl oleate with Tween 80 as emulsifier and n-pentanol as a co-emulsifier. BCTP was effective in reducing the cell numbers of L. monocytogenes, while TEOP was effective against all five organisms investigated. The abilities of these emulsions to reduce preformed biofilms of the five bacteria were also investigated. With the exception of the biofilm formed by L. monocytogenes, which surprisingly was not significantly affected by BCTP, all biofilms were inhibited by both BCTP and TEOP.

Determination of airborne trialkyl and triaryl organophosphates originating from hydraulic fluids by gas chromatography–mass spectrometry: Development of methodology for combined aerosol and vapor sampling

Methodology for personal occupational exposure assessment of airborne trialkyl and triaryl organophosphates originating from hydraulic fluids by active combined aerosol and vapor sampling at 1.5 L/min is presented. Determination of the organophosphates was performed by gas chromatography–mass spectrometry. Combinations of adsorbents (Anasorb 747, Anasorb CSC, Chromosorb 106, XAD-2 and silica gel) with an upstream cassette with glass fiber or PTFE filters and different desorption/extraction solvents (CS 2, CS 2–dimethylformamide (50:1, v/v), toluene, dichloromethane, methyl- t-butyl ether and methanol) have been evaluated for optimized combined vapor and aerosol air sampling of the organophosphates triisobutyl, tri- n-butyl, triphenyl, tri- o-cresyl, tri- m-cresyl and tri- p-cresyl phosphates. The combination of Chromosorb 106 and 37 mm filter cassette with glass fiber filter and dichloromethane as desorption/extraction solvent was the best combination for mixed phase air sampling of the organophosphates originating from hydraulic fluids. The triaryl phosphates were recovered solely from the filter, while the trialkyl phosphates were recovered from both the filter and the adsorbent. The total sampling efficiency on the combined sampler was in the range 92–101% for the studied organophosphates based on spiking experiments followed by pulling air through the sampler. Recoveries after 28 days storage were 98–102% and 99–101% when stored at 5 and −20 °C, respectively. The methodology was further evaluated in an exposure chamber with generated oil aerosol atmospheres with both synthetic and mineral base oils with added organophosphates in various concentrations, yielding total sampling efficiencies in close comparison to the spiking experiments. The applicability of the method was demonstrated by exposure measurements in a mechanical workshop where system suitability tests are performed on different aircraft components in a test bench, displaying tricresyl phosphate air concentrations of 0.024 and 0.28 mg/m 3, as well as during aircraft maintenance displaying tri- n-butyl phosphate air concentrations of 0.061 and 0.072 mg/m 3.

Dispersion-free solvent extraction of U(VI) in macro amount from nitric acid solutions using hollow fiber contactor

The applicability of dispersion-free solvent extraction (DFSX), through microporous hydrophobic membrane has been studied. The hollow fiber membrane contactor, with surface area of ∼381 cm 2 was employed to extract U(VI) in macro concentration (35 g dm −3) from aqueous acidic solutions. Prior to deployment of this technique for recovery of U(VI) from oxalate supernatant waste, chemical parameters such as extractant concentration, feed acidity, concentration of U(VI) in feed were studied. The study revealed that 30% tri- n-butyl phosphate (TBP) in n-dodecane as an extractant and feed in 3 M HNO 3 gave an optimum extraction of U(VI) and it was possible to strip back utilizing 0.05 M HNO 3. It was established to recover more than 90% of U(VI) from oxalate supernatant waste, which was often generated from nuclear chemical facilities.

Selective extraction of zinc(II) over iron(II) from spent hydrochloric acid pickling effluents by liquid–liquid extraction

The selective removal of zinc(II) over iron(II) by liquid–liquid extraction from spent hydrochloric acid pickling effluents produced by the zinc hot-dip galvanizing industry was studied at room temperature. Two distinct effluents were investigated: effluent 1 containing 70.2 g/L of Zn, 92.2 g/L of Fe and pH 0.6, and effluent 2 containing 33.9 g/L of Zn, 203.9 g/L of Fe and 2 M HCl. The following extractants were compared: TBP (tri- n-butyl phosphate), Cyanex 272 [bis(2,4,4-trimethylpentyl)phosphinic acid], Cyanex 301 [bis(2,4,4-trimethylpentyl) dithiophosphinic acid] and Cyanex 302 [bis(2,4,4-trimethylpentyl) monothiophosphinic acid]. The best separation results were obtained for extractants TBP and Cyanex 301. Around 92.5% of zinc and 11.2% of iron were extracted from effluent 1 in one single contact using 100% (v/v) of TBP. With Cyanex 301, around 80–95% of zinc and less than 10% of iron were extracted from effluent 2 at pH 0.3–1.0. For Cyanex 272, the highest extraction yield for zinc (70% of zinc with 20% of iron extraction) was found at pH 2.4. Cyanex 302 presented low metal extraction levels (below 10%) and slow phase disengagement characteristics. Reactions for the extraction of zinc with TBP and Cyanex 301 from hydrochloric acid solution were proposed.

Kinetic model of actinides and lanthanides extraction in non-stationary conditions

The influence of periodical oscillations of the temperature on extraction and stripping processes in the extraction systems is studied. Three extraction systems with tri- n-butyl phosphate (TBP) were investigated: No. 1, 6 M NaNO 3–Nd(NO 3) 3–Pr(NO 3) 3–TBP–kerosene; No. 2, [Nd(NO 3) 3·3TBP]–[Pr(NO 3) 3·3TBP]–kerosene–0.1 M HNO 3; No. 3, NaNO 3–Nd(NO 3) 3–Pr(NO 3) 3–TBP–kerosene–0.1 M HNO 3. Mathematical model of the non-stationary membrane extraction is enhanced including the dependence of extraction rate constants on temperature. The values of activation energy for direct and reverse reactions of extraction and stripping reactions of Pr and Nd were calculated. The mathematical model describes experimental data adequately. The optimal conditions of separation by liquid membrane were found.

Molecular modification of a novel macroporous silica-based impregnated polymeric composite by tri- n-butyl phosphate and its application in the adsorption for some metals contained in a typical simulated HLLW

Using tri- n-butyl phosphate (TBP) as a molecular modifier, a novel macroporous silica-based 4,4′,(5′)-di-( tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6) polymeric composite (DtBuCH18C6 + TBP/SiO 2–P) was synthesized. It was done by impregnating and immobilizing DtBuCH18C6 and TBP molecules into the pores of SiO 2–P particles utilizing an advanced vacuum sucking technique. The adsorption of 10 fission and non-fission products Sr(II), Ba(II), Ru(III), Mo(VI), Na(I), K(I), Pd(II), La(III), Cs(I), and Y(III) onto (DtBuCH18C6 + TBP)/SiO 2–P was investigated by examining the influence of contact time and the HNO 3 concentration in a range of 0.1–5.0 M at 298 K. It was found that at the optimum concentration of 2.0 M HNO 3 (DtBuCH18C6 + TBP)/SiO 2–P exhibited strong adsorption ability and high selectivity for Sr(II) over all of the tested elements, which showed very weak or almost no adsorption except Ba(II). Moreover, the quantity of DtBuCH18C6 leaked from (DtBuCH18C6 + TBP)/SiO 2–P in 2.0 M HNO 3, 326.2 ppm, was obviously lower than 658.4 ppm that leaked from DtBuCH18C6/SiO 2–P. This was ascribed to the effective association of DtBuCH18C6 and TBP through intermolecular interaction, i.e., hydrogen bonding. The significant reduction of DtBuCH18C6 leakage by molecular modification with TBP was achieved. It was of great benefit to application of the (DtBuCH18C6 + TBP)/SiO 2–P polymeric composite in chromatographic partitioning of Sr(II), one of the main heat generators, from high level liquid waste (HLLW) in reprocessing of nuclear spent fuel in MAREC process developed recently.

Extraction and separation of yttrium from the rare earths with sec-octylphenoxy acetic acid in chloride media

Extraction and separation of yttrium from the rare earths in chloride medium using sec-octylphenoxy acetic acid (CA-12), tri- n-butyl phosphate (TBP) as modifier, in kerosene has been investigated. The separation coefficients, β, were obtained and the extraction selectivity has been enhanced when compared with that of naphthenic acid. The experimental results indicated that CA-12–TBP system could be employed to separate yttrium from rare earths. Fractional extraction (15 stages for extraction and 10 stages for scrubbing) was studied, the raffinate of the first stage was abundant in purity yttrium of 99.5%, with a yield of >95%, percentage of yttrium in the mixture rare earths was less than 5% in the loaded organic phase of the 25th stage and loaded capability was about 0.2 mol/L.

Remarkable effect of hydrogen-bonding interaction on stereospecificity in the radical polymerization of N-vinylacetamide

Radical polymerization of N-vinylacetamide (NVA) in toluene at low temperatures was investigated. It was found that the addition of Lewis bases or alcohol compounds significantly influenced stereospecificity in NVA polymerization. For example, syndiotacticity increased from 25% to 34% by adding tri- n-butyl phosphate at −40 °C. Mono-alcohol compounds increased heterotacticity and heterotactic poly(NVA) with mr triad content of 58% was obtained at −40 °C in the presence of 1,1,1,3,3,3-hexafluoro-2-propanol. Furthermore, isotactic poly(NVA) with mm triad = 49% was obtained at −60 °C in the presence of diethyl l-tartrate. The NMR analysis demonstrated that complex formation between NVA monomer and the added agents, through hydrogen-bonding interaction, played an important role to induce the stereospecificity.

Study of Electron Donor–Acceptor Complex Formation of o-Chloranil With a Series of Phosphine Oxides and Tri- n-butyl Phosphate by the Absorption Spectrometric Method

Electron donor–acceptor (EDA) complex formation of o-chloranil with six different phosphine oxides and tri-n-butyl phosphate (TBP) has been studied in CCl 4 solution by the UV-VIS absorption spectrophotometric technique. An absorption band due to a charge–transfer (CT) transition is observed in the visible region. Utilizing the CT transition energy, the electron affinity of o-chloranil in solution has been calculated. Degrees of charge transfer, and oscillator and transition dipole strengths have also been calculated for all of the investigated EDA complexes. Except for TBP, other phosphine oxides, viz., tri-n-octyl phosphine oxide, tri-n-butyl phosphine oxide, triphenyl phosphine, octyl(phenyl)-N,N-diisobutylcarbamoylphosphine oxide, octyl(phenyl)-N,N-dicyclohexylcarbamoylmethylphosphine oxide and octyl(phenyl)-N,N-diisopropylcarbamoylmethylphosphine oxide have been shown to form stable 1:1 EDA complexes with o-chloranil. The complex of TBP with o-chloranil decays slowly into a secondary product. Formation constants of the EDA complexes have been determined.

A zinc-selective electrode based on N, N′-bis(acetylacetone)ethylenediimine

The potentiometric response characteristics of electrodes based on N, N′-bis(acetylacetone)ethylenediimine ( I) in poly(vinyl chloride) (PVC) combined with an anion localizing agent (sodium tetraphenyl borate, NaTPB) and solvent mediators, viz. o-nitrophenyl octyl ether (NPOE), dibutyl (butyl) phosphonate (DBBP), tri- n-butyl phosphate (TBP) and chloronaphthalene (CN) were investigated. The best result for Zn 2+-sensing was obtained for the electrode membrane of the composition of I:PVC:NaTPB:NPOE = 5:100:6:200, where the electrode had a Nernstian response (30.0 mV/decade of Zn 2+ activity) to Zn 2+ within the concentration range of 1.0 × 10 −6 to 1.0 × 10 −1 M. The operational pH range of the electrode was 3.2–7.1. Selectivity characteristic of the proposed electrode was also assessed by calculating K A , B Pot with a fixed interference method. The sensor has been successfully used in real sample analysis and also in the potentiometric titration of zinc ions with EDTA.

A copper-selective electrode based on bis(acetylacetone)propylenediimine

The potentiometric response characteristics of Cu 2+-selective electrodes based on bis(acetylacetone)propylenediimine ( I) combined with anion localizing agent (sodium tetraphenyl borate (NaTPB)) and solvent mediators (dibutyl butyl phosphonate (DBBP), tri- n-butyl phosphate (TBP) and chloronaphthalene (CN)) were investigated. The best results for Cu 2+ sensing was obtained for the electrode membrane containing PVC, I, DBBP and NaTPB in composition 5:100:200:6 ( I:PVC:DBBP:NaTPB) (w/w; mg), where the electrode had a Nernstian response (30.0 mV/decade) to Cu 2+ within the concentration range 1.0 × 10 −5 to 1.0 × 10 −1 M and detection limit of 0.5 ppm. The operational pH range of the electrode was 3.3–7.0. Selectivity characteristic of the proposed electrode was also assessed by calculating K A , B Pot using fixed interference method matched potential method. The sensor has been successfully used in the potentiometric titration of copper ions with EDTA.

Holmium nitrate complexation with tri- n-butyl phosphate in supercritical carbon dioxide

Holmium nitrate pentahydrate was reacted with tri- n-butyl phosphate in supercritical carbon dioxide at 308 K. The products of the complexation reaction were measured under supercritical fluid conditions using UV–vis spectroscopy. The solubility of the metal complexes in the supercritical fluid phase was measured. The mole-ratio titration method was used to determine the stoichiometry of the soluble complexes. Conditional extraction coefficients were calculated from spectral data using least-squares regression and hard-equilibria models. Data indicate that the holmium nitrate–tributyl phosphate system forms 1:2 and 1:4 holmium–tributyl phosphate complexes. Conditional extraction coefficients were calculated as log K ex2 = 5.8 ± 0.1 and log K ex4 = 3.1 ± 0.1 giving a log K ext value of 8.9 ± 0.1. The conditional formation constant for the reaction M L 2 ( scf ) + 2 L ⇌ M L 4 ( scf ) + 2 H 2 O in the supercritical fluid phase was calculated as log β 204(scf) = 2.4 ± 0.1.

Determination of trace elements in uranium oxide by Total Reflection X-ray Fluorescence spectrometry

A study on the applicability of Total Reflection X-ray Fluorescence for the determination of multielements in trace amounts in U 3O 8 matrix has been made. The calibration of the Total Reflection X-ray Fluorescence spectrometer and the validation of the method were done using multielement standards. The trace elements present in U 3O 8 standards and samples were determined after separating the U matrix by solvent extraction using tri- n-butyl phosphate and trioctyl phosphine oxide as extractants. From the aqueous phase the elements K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Rb, Sr, Y, Zr, Pb and Ba, etc., were determined by Total Reflection X-ray Fluorescence using Ga as an internal standard. An intercomparison of the Total Reflection X-ray Fluorescence determined concentrations of the trace elements specific to nuclear fuel, e.g. Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn in U 3O 8 standards/samples with certified concentrations for these elements in U 3O 8 standards and Inductively Coupled Plasma Atomic Emission Spectroscopy determined concentrations in real U 3O 8 samples was also made. The method shows a precision and accuracy better than 5% (1 σ) for most elements in concentration range of ng/mL with a sample size of 10 μL.

Studies on recovery of hexavalent chromium from plating wastewater by supported liquid membrane using tri- n-butyl phosphate as carrier

The transport of chromium(VI) ions from an aqueous feed solution through a flat type supported liquid membrane (SLM) containing tri- n-butyl phosphate (TBP) as carrier was studied. The influence of pH on the source phase, effect of concentration of receiving phase, stirring speed, effect of initial Cr(VI) concentration, feed to strip ratio and the influence of support characteristics was studied. Polytetrafluoroethylene (PTFE) with 1.0 μm pore size was found to have more flux permeability than 0.50 μm. The results indicated that the aqueous feed solution at pH 1 ± 0.1 to have high permeability. The initial feed phase Cr(VI) concentration of 9.6 × 10 − 4 M can be completely extracted and stripped with 0.50 M sodium hydroxide as stripping solution within 8 h. Stirring of aqueous solutions at 500 rpm with a magnetic stirrer showed high transport rate. After ten transport studies with one impregnation of carrier, the TBP carrier showed no significant loss in its permeability and retained the same transport ability. Under the optimum conditions chromium(VI) recovery from real plating wastewater was tested and found to be satisfactory with a flux value of 1.4 × 10 − 3 mol/m 2/s.

Dissolution and extraction of actinide oxides in supercritical carbon dioxide containing the complex of tri- n-butylphosphate with nitric acid

Dissolution of individual actinide oxides (Th, U, Pu, Np), or their mechanical mixtures, as well as of solid solutions U–Pu, U–Np, U–Am and U-Pu-Eu oxides in supercritical fluid carbon dioxide (SF-CO 2) containing the complex of tri- n-butyl phosphate (TBP) with nitric acid (TBP–HNO 3) has been investigated. The effect of the calcination temperature of solid solutions of dioxides on the separation of actinides during supercritical fluid extraction (SFE) has been studied as well. It was shown for the first time that milligram amounts of uranium dioxide could be quantitatively dissolved in (SF-CO 2) containing the TBP–HNO 3 complex and efficiently separated from Pu, Np, and Th during SFE of mechanical mixture of these oxides. On the contrary, both U and Pu are quantitatively dissolved in SF-CO 2–TBP–HNO 3 during SFE from solid solutions of U–Pu dioxide. An increase of the calcination temperature of the mixed U(IV)–Pu(IV) dioxide from 850 to 1200 °C has no influence on the relative extraction yield of these actinides during SFE. To cite this article: T. Trofimov et al., C. R. Chimie 7 (2004).

Supercritical fluid extraction of rare earth elements from luminescent material in waste fluorescent lamps

Rare earth elements were extracted from luminescent material in waste fluorescent lamps using supercritical carbon dioxide (SF-CO 2) containing tri- n-butyl phosphate (TBP) complexes with HNO 3 and H 2O. The determined Y, Eu, La, Ce and Tb in the employed luminescent material were 29.6, 2.3, 10.6, 5.0 and 2.6 wt.%, respectively. Aqueous droplets were generated in an extraction experiment from a reaction with metal oxides and a complex prepared from vigorous mixing of TBP with concentrated nitric acid (15.5 mol dm −3 (M)). These droplets were generated because the complex was saturated with water and the excess water separated, leading to low recovery yields. The molecular ratio of TBP:HNO 3:H 2O in the complex was 1.0:1.8:0.6. When the ratio was changed to 1.0:1.3:0.4 by dilution with TBP anhydrate, the separation of water was prevented. Using this complex, extraction efficiencies for Y and Eu increased to over 99% after the static extraction for 120 min at 15 MPa, 333 K.

PVC based 5,10,15,20-tetrakis (4-methoxyphenyl) porphyrinatocobalt(II) membrane potentiometric sensor for arsenite

PVC based membranes of 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrinatocobalt(II) (TMOPP-Co) ( I) as electroactive material with dibutyl butyl phosphonate (DBBP), dioctyl phthalate (DOP), 1-chloronaphthalene (CN), tri- n-butyl phosphate (TBP) and tris(2-ethylhexyl) phosphate (TEP) as plasticising solvent mediators have been prepared and tried for arsenite determination. The membrane having a composition 150:5:150 (PVC: I:DBBP) exhibited the best results with linear potential response in the concentration range of 7.9 × 10 −5 to 1.0 × 10 −1 M of AsO 2 − with a slope of 28.8 mV/decade. The useful pH range of the sensor is 6.0–10.5. The membrane worked satisfactorily in non-aqueous medium up to 5% (v/v) non-aqueous content. The selectivity coefficient values for mono- and divalent anions indicate good selectivity for arsenite over a large number of anions.

Liquid–liquid equilibria in the system H 3PO 4–KCl–H 2O–tri- n-butyl phosphate: experiments and modelling

The liquid–liquid equilibria of the system H 3PO 4–KCl–H 2O–TBP was studied experimentally in the concentration range 0–6 mol/kg. The obtained data were modelled using the Pitzer equation for the aqueous phase and the Sergievskii–Dannus relationship for the organic phase. A fairly good agreement was observed between the model and the experimental data.

Ultrasonic investigations in binary mixtures of some commercial extractants: liquid ion exchanger reagents and tri- n-butyl phosphate

The ultrasonic velocities, viscosities and densities of the binary mixtures of some commercial solvent extractants liquid ion exchanger LIX 84, LIX 622, LIX 860, LIX 984 and tri- n-butyl phosphate (TBP) have been experimentally obtained over the entire mole fraction range of the components at 303.15 K. The thermoacoustic parameters and their excess functions have been computed from the experimental data and used to shed light upon the molecular interactions present in the polar–polar-type binary systems. The experimentally determined velocities have been compared with theoretically estimated values obtained using different empirical theories and relations. The results are utilised to compare the relative merits of these theories and relations in terms of percentage of variation.

Decontamination of uranium oxides from solid wastes by supercritical CO 2 fluid leaching method using HNO 3–TBP complex as a reactant

A new method referred to as supercritical CO 2 fluid leaching (SFL), which is based on selective dissolution of uranium oxides with the supercritical CO 2 fluid containing the HNO 3–tri- n-butyl phosphate (TBP) complex, has been developed for the removal and recovery of uranium from solid wastes contaminated by uranium oxides. A recommended SFL procedure has been established consulting experimental results of the complexation efficiency of the uranium oxides and the dissolution efficiency of U(VI)–TBP complex at different pressures. The recommended method consists of complexation process at 60 °C and 15 MPa for 150 min using the supercritical CO 2 containing the HNO 3–TBP complex and dissolution process at 60 °C and 20 MPa using a flow of the neat supercritical CO 2. The complexation–dissolution cycle is repeated twice. The feasibility of the recommended procedure to the removal of uranium from the solid wastes was demonstrated using synthetic wastes that were a mixture of standard sea sand (50 g) and UO 2 or U 3O 8 powders (20–200 mg of U). The decontamination factor of UO 2 or U 3O 8 was determined to be higher than 5×10 2. The solid waste after the SFL treatment was dry and contained enough low concentrations of TBP and HNO 3.