Organic Phase Ratio Research Articles

Hydrolysis of tri-butyl phosphate in n-dodecane using sodium hydroxide: Factors affecting the hydrolysis process

Alkaline hydrolysis of tri-n-butyl phosphate (TBP) in n-dodecane (n-DD) using sodium hydroxide was studied for the treatment and disposal of spent organic waste generated from nuclear reprocessing plants. Experiments were performed in a stainless steel autoclave with a process volume of about 1 L to investigate the effect of agitator speed, temperature, organic to aqueous phase ratio, and concentration of sodium hydroxide on the kinetics of TBP hydrolysis. The concentration of TBP gradually decreased with increase in the duration of hydrolysis followed by a sharp fall in the concentration of TBP due to autocatalytic hydrolysis of TBP. The diluent does not take part in the hydrolysis reaction which was evident from the third phase formation during the course of hydrolysis. The present study confirms the complete conversion of TBP to its aqueous soluble products during hydrolysis. The results showed that among the various parameters studied, the concentration of NaOH and temperature were the key factors in determining the rate of hydrolysis of TBP. By using 12.5 M NaOH, aqueous phase to organic phase ratio above 1/3, temperature above 353 K, at an agitation speed of 1000 rpm, nearly complete hydrolysis of 1.1 M TBP was achieved in less than 3 h.

A New Application of Solvent Extraction to Separate Copper from Extreme Acid Mine Drainage Producing Solutions for Electrochemical and Biological Recovery Processes

Over the last decade, AMD waters have gained more attention as a potential source of metals due to the emerging need to recover or recycle metals from secondary resources. Metals recovery supports sustainability and the development of a circular economy with benefits for resource conservation and the environment. In this study, five extractants (Acorga M5640, LIX 54, LIX 622, LIX 622 N, and LIX 864) diluted (15% (v/v)) in Shell GTL with 2.5% (v/v) octanol were compared and evaluated for Cu recovery from an extreme AMD sample (5.3 ± 0.3 g/L Cu) collected at the inactive São Domingos Mine in the Iberian Pyrite Belt of Portugal. Of the five extractants, Acorga M5640 showed the best selective efficiency. Further tests showed that 30% (v/v) of this extractant was able to selectively extract ≈ 96.0% of the Cu from the AMD in one extraction step and all of the remaining Cu (to below detection) in three steps. Among the different stripping agents tested, 2 M sulfuric acid was the most efficient, with ≈ 99% of the Cu stripped, and the recyclability of the organic phase was confirmed in five successive cycles of extraction and stripping. Furthermore, contact time tests revealed that the extraction kinetics allows the transfer of ≈ 97% of the Cu in 15 min, and aqueous to organic phase ratios tests demonstrated a maximum loading capacity of ≈ 16 g/L Cu in the organic phase. Raising the concentration of Cu in the stripping solution (2 M sulfuric acid) to ≈ 46 g/L through successive striping steps showed the potential to recover elemental Cu using traditional electrowinning. Finally, a biological approach for Cu recovery from the stripping solution was evaluated by adding the supernatant of a sulfate-reducing bacteria culture to make different molar ratios of biogenic sulfide to copper; ratios over 1.75 resulted in precipitation of more than 95% of the Cu as covellite nanoparticles.Graphical

Preparation and evaluation of targeted albumin lipid nanoparticles with lactobionic acid for targeted drug delivery of sorafenib in hepatocellular carcinoma

Sorafenib (SF) is an anticancer drug used to treat hepatocellular carcinoma (HCC), but it is associated with a wide range of side effects. The objective of this research was to prepare SF-loaded albumin lipid nanoparticles (ALNs) consisting of medium-chain triglycerides and lactobionic acid-human serum albumin conjugate (LA-HSA conjugate) as a targeted drug delivery system of SF for the treatment of HCC. HSA was modified with ethylenediamine and conjugated to LA as a targeting agent. ALNs were characterized concerning particle size, zeta potential, drug encapsulation efficiency, and in vitro drug release. The cytotoxicity and cellular uptake of the targeted and untargeted ALNs were also evaluated in HepG2 cells. The results showed that the optimized targeted ALNs, which consisted of 10% (w/v) of HSA-LA, 5% (w/v) of poloxamer, and 5% of organic phase ratio with 0.1% (w/v) of lecithin, showed the particle size of 280.1 ± 4.4 nm, the zeta potential of −12.3 ± 0.9 mV, and the entrapment efficiency of 97.6 ± 2.2%. MTT assay and cellular uptake studies showed that the targeted ALNs had more cytotoxicity and cellular uptake than the untargeted ones in HepG2 cells (P < 0.05). Overall, the targeted delivery system reported here can enhance the therapeutic efficacy of SF in HCC.

Solvent extraction of titanium(IV) from sulfuric acid solution with Cyanex923 and its application in leach liquor of red mud

The extraction behavior of Ti(IV) from sulfuric acid solutions using Cyanex923 has been investigated. The effects of the concentration of H2SO4 and SO42- in the aqueous phase, the extractant concentration in the organic phase, phase ratio, equilibrium time and temperature were studied. Then, the extraction mechanism and thermodynamics of the process were discussed. The load capacity of Cyanex923 for Ti(IV) was also investigated. The selectivity of Ti(IV) with vanadium (V) and iron (Fe) was investigated at different acidity. Furthermore, a selective titanium separation from the sulfuric acid liquor of red mud can be done efficiently using Cyanex923 as extractant.

Synthesis of chelating N-hydroxyl amine derivative and its application for vanadium separation from Abu Zeneima ferruginous siltstone ore, Southwestern Sinai, Egypt

ABTRACT To extract vanadium (V) ions from the ferruginous siltstone at Abu Zeneima in Southwestern Sinai, Egypt, a synthesized chelating N-phenyl acetyl-N-naphthyl hydroxyl amine (PANHA), was used. Complete characterization was carried out successfully to elucidate the structure using several techniques such as FT-IR,1H-NMR, 13C-NMR, GC-MS and TGA analysis performances. Improved experimental measurements, such as pH, shaking time, initial concentration of V(V), PANHA dosage, temp., and stripping agents, have been achieved with the solvent extraction technique. At 25 ℃ and 0.015 mole per liter through 30 minutes, PANHA/CHCl3 has an extreme retention potential of 50 mg per gram at 25 ℃ at pH 1.5 at 1:1 aqueous to organic phase ratio. The linear regression analysis, consisting of a log D track versus pH, shows a straight line with a slope of 0.859, indicates that a mole of H+ was released during the extraction. The stability constant (β), of PANHA-V(V) complex was calculated from the intersection (log β=1.7958), and it was found to equal 63.1. The stoichiometry mechanism among a chelating ligand of PANHA and V(V) indicates a roughly linear correlation with slope of 0.882 which explains that one mole of PANHA chelating ligand can react with one mole of V (V). According to the kinetic and thermodynamic interpretations, the pseudo-second order kinetic model predicted the kinetics of vanadium (V) extraction, the thermodynamic factors ΔS, ΔH, and ΔG were also measured. As the temperature rises, ∆G values rise from -10.45 kJ/mol at 198 K to -2.2 kJ/mol at 353 K. Vanadium may be stripped from the loaded PANHA/CHCl3, by 0.5M NaOH with a 99% efficiency rate. To obtain a vanadium concentrate (NH4VO3, AMV) with a vanadium content of 42.6 percent and pureness of 98 percent, the enhanced variables were finally put to use.

Purification of recovered phosphoric acid by extracting aluminium with di-2-ethylhexyl phosphoric acid

The extraction of aluminium from dilute phosphoric acid with di-2-ethylhexyl phosphoric acid (DEHPA) was optimized using response surface methodology. The optimization was based on the experimental three-level central composite face-centred design (CCF) and was conducted on real-life samples. The three variables included were pH, extractant concentration and aqueous to organic phase ratio (AO). Under the optimized conditions (pH 2.5, 0.6 M DEHPA and AO ratio 1:2), extraction efficiency of 99% for aluminium in four extraction stages is achieved. The purified phosphoric acid solution can then be utilized by the fertilizing industry. Stripping tests for organic phase loaded with aluminium were conducted with sulphuric acid. Extremely high stripping efficiency was obtained with 0.9 M sulphuric acid resulting in the recovery rate of 88% in one stage. After stripping, the aluminium sulphate solution can be reused as a precipitation agent for phosphorus in the wastewater treatment process.

5-HMF production from industrial grade sugar syrups derived from corn and wood using niobium phosphate catalyst in a biphasic continuous-flow tubular reactor

This work demonstrated the promise of using industrial-grade sugar syrups derived from corn and wood, i.e., high fructose corn syrup (HFCS), glucose corn syrup (GCS) and wood-based sugar (TMP-Bio Sugar), as cheaper and competitive feedstocks for 5-HMF production using niobium phosphate as a heterogeneous solid acid catalyst in a biphasic continuous-flow tubular reactor. 5-HMF yield as high as 53.1% with 100% sugar (glucose and fructose) conversion was obtained from catalytic dehydration of HFCS-90 (containing 90 wt% fructose) at 150 °C, with feed concentration of 200 mg/ml (glucose and fructose) and aqueous to organic phase ratio of 1:5 (v/v). Catalyst stability with time was tested over 20 h of continuous-time on stream, and the reusability of the catalyst was studied after in-situ regeneration of the used catalyst by calcination in the air for removing the deposited humins and coke on the surface of the catalyst particles. The regenerated catalyst showed good activity with almost constant selectivity, although at lower glucose conversion and reduced 5-HMF yield compared to the fresh catalyst, indicating that the in-situ regeneration process could recover a part of the acid sites on the catalyst surface. The produced humins during the reaction were characterized by Fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA) and elemental analysis (CHNS). The results showed high aromaticity and the presence of a high degree of unsaturated compounds in the structure of humins.

Conversion of waste cooking oil into value-added emulsion liquid membrane for enhanced extraction of lead: Performance evaluation and optimization

This research study investigated the synthesis of environmentally benign green emulsion liquid membrane (GELM) employing waste cooking oil (WCO) as diluent. The emulsion was prepared using D2EHPA as the carrier, Span 80 as surfactant, and sulphuric acid as internal/stripping agent. The influence of nine operating variables namely, Span 80 concentration, D2EHPA concentration, shaking time, shaking speed, pH of the feed, treat ratio (TR), H2SO4 concentration, lead concentration in feed, and volume ratio of organic phase to aqueous phase (O/A) on the performance of lead extraction was studied. Plackett Burman design (PBD), was employed for the screening of variables. The Pareto analysis shows that six variables were the most significant variables at the confidence level of 95%. The selected variables were then screened applying Box-Behnken design (BBD). The optimum values of the variables were: D2EHPA concentration – 4.6 (v/v%), Span 80 concentration – 2.14 (v/v%), pH of the feed – 4.4, internal phase (H2SO4) concentration – 2 M, initial lead concentration – 173 ppm, phase ratio (O/A) – 1.3. At these optimum conditions, a maximum lead extraction of 97.39% was obtained. The mechanism for the extraction of lead was analyzed. Reuse and recycling of membrane phase show that the GELM can be recycled for 7 cycles without reduction in lead extraction efficiency. Kinetic analysis of lead extraction was performed using zero, first, and second-order model at optimum condition. The experimental data fitted well with first-order (R2 – 0.9653). Thermodynamic studies indicated that the extraction procedure is endothermic, spontaneous in nature.

Recovery of indium from jarosite residues of zinc refinery by a hydrometallurgical process

Indium is a strategic element essential in technological development; its recovery from jarosite produced as waste in a Zn refinery operated using a hydrometallurgical flowsheet was studied. Indium content in the residue was 86 mg/kg. A laboratory optimization for the indium extraction processes was done using multifactorial regression analysis. First, the optimal leaching conditions were determined: stirring time 97.7 h; HCl concentration 6.8 M and using a ratio 9.403 g of residue per 50 mL of leaching solution obtaining 96.8% of leaching yield. Secondly, two extraction methods were evaluated, using either a solvent extraction or polymeric inclusion membranes. The proposed optimal conditions for solvent extraction are: aqueous to organic phase ratio 10; feeding phase pH 3.0, 40%(V/V) D2HEPA in kerosene and a stirring time of 4.5 min with 2 consecutive extractions resulting in 83.2% of indium recovery, giving an indium concentration of 97.1 mg/L. The optimal conditions for indium recovery using polymeric inclusion membranes are: stirring time of 3.1 h, a mass ratio of 1.44 (mD2HEPA/mPVC), a feeding phase pH = 3.0 and [HCl] 6.0 M in the re-extraction phase with 100% indium recovery and an indium concentration of 110 mg/L after ten extractions. The polymer inclusion membranes (PIMs) offer more advantages for indium recovery because of its high reusability, lower cost, simple operation process and little environmental pollution. The co-extraction of Fe(III) was minimized, reducing Fe(III) to Fe(II) using Fe° and Sn(II). A selective precipitation using ammonia was carried out to enrich and purify indium, and to recover it in solid form as indium hydroxide. The methodology proposed in this study that managed to efficiently extract In from a metallurgical waste could be the basis for developing methodologies to the extraction of In and/or other strategic elements from other metallurgical waste, given the reuse of these wastes as alternative sources of strategic elements.

Catalytic dehydration of glucose to 5-HMF using heterogeneous solid catalysts in a biphasic continuous-flow tubular reactor

This work aimed to produce 5-hydroxymethylfurfural (5-HMF) from glucose in a biphasic continuous-flow tubular reactor with various heterogeneous solid acid catalysts or combined solid acid-base catalysts. Among the catalysts tested, niobium phosphate (NbP) was found to be the most active catalyst for glucose dehydration with a maximum 5-HMF yield of 45% at 150 °C. The higher activity of NbP was attributed to its higher total number of acid sites and BET surface area, as well as the presence of both Lewis acid and Brønsted acid sites. The effects of different operating conditions such as aqueous to organic (A/O) phase ratio, reaction temperature and feeding flow rate on the activity of some selected catalysts were studied. Reducing A/O ratio by increasing the extracting organic phase flow rate and increasing the reaction temperature (up to 150 °C) were found to positively affect 5-HMF production from glucose in the presence of NbP. Kinetics study demonstrated that the overall reaction of glucose dehydration to 5-HMF over the NbP catalyst is a first-order reaction with the reaction rate constants (k) determined as 0.06, 0.21 and 0.6 min−1 at 110, 130 and 150 °C, respectively, and the apparent activation energy (Ea) calculated to be 77 kJ/mol.

Box-Behnken design aided optimization and validation of developed reverse phase HPLC analytical method for simultaneous quantification of dolutegravir sodium and lamivudine co-loaded in nano-liposomes.

A stability-indicating reversed-phase high-performance liquid chromatography method for simultaneous estimation of dolutegravir sodium and lamivudine encapsulated in the nanoliposomal formulation was developed. The chromatographic parameters namely, organic phase ratio, flow rate, and sample injection volume were selected as independent factors and were optimized by multivariate Box-Behnken design. Responses analyzed were retention time, peak area, and resolution. The optimized chromatographic method with Hypersil BDS C8 CN column as stationary phase and methanol and acetonitrile mixture and acidified Milli-Q water (pH 2.8, adjusted with 0.02% v/v orthophosphoric acid) as the mobile phase in an isocratic elution mode was validated according to parameters of International Conference on Harmonization Q1(R2) guidelines. The validated reversed-phase high-performance liquid chromatography method exhibited specificity for both dolutegravir sodium and lamivudine in the presence of degradation products as well as the liposomal matrix. This method was effectively utilized to determine the amount of drug entrapped and drug loading efficiency of dolutegravir sodium and lamivudine in a nano-liposomal formulation.

Neodymium naphthenate-loaded organic phase stripping using sodium oxalate

Neodymium naphthenate-loaded organic phase stripping using sodium oxalate solution was studied to explore the feasibility of synchronous rare earth-loaded organic phase stripping, rare earth precipitation, and blank organic phase saponification. Experimental results show that loaded organic phase stripping, rare earth precipitation, and blank organic phase saponification can be realized simultaneously. When using 20% excess of sodium oxalate over the stoichiometry with the volume ratio of organic phase to aqueous phase of 1:1 at 25 °C for 40 min, the single stage stripping rate and saponification value are about 40% and 0.29 mol/L, respectively. After 16 stages of countercurrent continuous stripping, the stripping rate of neodymium can reach 99%, the saponification value is 0.42 mol/L, the Nd3+ concentration in saponified organic phase is less than 0.0020 mol/L, and the main phase in precipitation is Nd2(C2O4)3·10H2O. Afterwards, this saponified organic phase can be used in the extraction of NdCl3 solution, and then the loaded organic phases (neodymium naphthenate) with 0.16 mol/L Nd3+ can be retrieved. The morphology, particle size distribution, and composition of the Nd2(C2O4)3·10H2O products are similar to those of the current direct precipitation products. The neodymium oxide prepared by continuous calcination of neodymium oxalate meets the national standard of China (GB/T 5240−2015). These results prove the feasibility of stripping neodymium naphthenate-loaded organic phase by using sodium oxalate solution. Sodium oxalate can serve as a stripping agent, a saponifier, and a precipitator, thereby simplifying rare earth extraction and separation. This study provides theoretical and technical support for the development of a novel method for rare earth extraction and separation.

Formulation and Evaluation of Baclofen Polymeric Nanoparticles for Transdermal Delivery In-vitro and Ex-vivo Optimization

Objectives: Baclofen is a skeletal muscle relaxant with an anti-inflammatory effect. The current market products of baclofen are oral tablets and intrathecal injection which cause many undesirable systemic side effects. This study aimed to formulate topical formula of baclofen to decrease systemic side effects. Topical drug delivery systems formulated as nanoparticles (NPs) enhanced the low drug release and the low bioavailability of the traditional gels. This occurs by prolonging the contact time and increasing the permeability of the drug through the skin. Methods: In this study, formulae of the baclofen-loaded Eudragit® RL100 (ERL) NPs were prepared by nanoprecipitation method. Polyvinyl alcohol (PVA) was added as a stabilizer. The NPs were characterized by measuring their particle size, polydispersity index (PDI), zeta potential, and entrapment efficiency percent (EE %) values. Their spherical morphology was confirmed using transmission electron microscopy (TEM). Viscosity was also measured. In vitro release and permeation studies were done to evaluate the release of the drug from the NPs gel and the permeability of the drug through the skin. The results were compared with formulated baclofen traditional gel. Results: ERL concentrationand organic phase ratio were the main factors affecting the NPs formulation. A decrease in the particle size was observed with an increase in ERL% while the smallest particle size was observed with formulae containing organic phase (acetone: methanol) in the ratio of 1: 3. The highest EE% was observed with the highest ERL concentration and the same organic phase ratio (acetone: methanol 1:3). Formulae B3, B6, B9 were selected for their most promising results. Their particle size was 187.4 ±2.81, 126.3 ±1.47, 120.0 ±1.06 nm and their EE% was 78.9 ±0.30, 83.3 ±0.26, and 86.6 ±1.12, respectively. The percentages of the drug released from the selected formulae as well as the percentage of the permeated drug were significantly higher than that of the baclofen traditional gel. Conclusion: ERL NPs were capable of releasing baclofen and improving its permeability through the skin so it may be considered as a suitable promising alternative drug delivery system.

Quantitative Determination of Rutin in Biological Samples of Rats Upon Administration of Primula veris L. Herbal Dense Extract

Rutin contents in biological samples of blood plasma, cardiomyocytes, and mitochondria of cardiomyocytes in rats after administration of Primula veris L. dense herbal extract were determined using a quantitative HPLC method. The optimum conditions for quantitative determination of rutin were KH2PO4 buffer (50 mM, pH 4.6), 82:18% (v/v) aqueous to organic phase ratio, 30°C, detection at 205 nm, flow rate 1 mL/min, 12 MPa pressure in chromatographic system, and retention time 6 – 6.5 min. Rutin was found to enter the blood and distribute into the heart, in which its concentration was 5.34 times higher than in blood, and to penetrate mitochondria, in which its concentration was 1.7 times higher than in plasma and 3.18 times lower than in the heart.

A robust optimization approach for the breast cancer targeted design of PEtOx-b-PLA polymersomes

The equipping of nanoparticles with the peptide moiety recognizing a particular receptor, enables cell or tissue-specific targeting, therefore the optimization of the targeted nanoparticles is a key factor in the formulation design process. In this paper, we report the optimization concept of Doxorubicin encapsulating PEtOx-b-PLA polymersome formulation equipped with Peptide18, which is a breast cancer recognizing tumor homing peptide, and the unveiling of the cell-specific delivery potential. The most dominant formulation parameters, which are the polymer to Doxorubicin mass ratio (w/w) and the aqueous to organic phase ratio (v/v), were optimized using Central Composite Design (CCD) based Response Surface Methodology. The characteristics of optimum polymersome formulation were determined as the hydrodynamic diameter of 146.35 nm, the PDI value of 0.136, and the encapsulation efficiency of 57.11% and TEM imaging, which are in agreement with the DLS data, showed the spherical morphology of the polymersomes. In order to demonstrate the breast cancer-specific delivery of targeted polymersomes, the flow cytometry and confocal microscopy analyses were carried out. The targeted polymersomes were accumulated 8 times higher in AU565 cells compared to MCF10A cells and the intracellular Doxorubicin was almost 10 times higher in AU565 cells. The CCD-mediated optimized targeted polymersomes proposed in this report holds the promise of targeted therapy for breast cancer and can be potentially used for the development of novel treatments.

Study on Extraction Separation of Thioarsenite Acid in Alkaline Solution by -Type Tri-n-Octylmethyl-Ammonium Chloride.

To overcome the problem of arsenic separation and enrichment from an alkaline leaching solution in arsenic-containing dust, a -type tri-n-octylmethyl-ammonium chloride (TOMAC) method for extracting thioarsenite is proposed in this paper. Considering an alkaline leaching solution as the research object, after vulcanization pretreatment, TOMAC transformation and organic phase saturated extraction capacity were measured, and the extraction mechanism was preliminarily studied. First, Cl−-type quaternary ammonium salt was effectively transformed to -type by treating organic phase with saturated NaHCO3five times. TOMAC was effectively transformed from to type by alkaline washing with 1.0 mol/l NaOH solution; this washing was repeated thrice. Thereafter, the effects of organic phase composition, phase ratio, extraction time, and temperature on the extraction and separation of arsenic were investigated. The results show that under the conditions of 30% -type TOMAC + 15% sec-octanol + 55% sulfonated kerosene, VO/VA = 1/1, and 5 min extraction at room temperature, the single-stage extraction rate of AsIII is 85.2%. The AsIII concentration in raffinate can be reduced to less than 1.33 × 10−3 mol/l by four-stage countercurrent extraction, and the extraction rate of AsIII can exceed 98.4%.

A Perspective View on Formulation and Optimization of Curcumin Loaded Phycocyanin Nanosponges

Curcumin have a wide range of pharmacological activity and used in various disorders. Due to its poor bioavailability and fast metabolism peripherally, it is a major obstacle for researchers. Recent research on nanotechnology paved the way to overcome above concern and good results were obtained in formulation of curcumin using nanotechnology. The main objective of the study is to optimize, formulate &amp; develop the curcumin loaded phycocyanin nanosponges and determine the variation in responses with respect to factors. The nanosponges were prepared using solvent evaporation technique and the final curcumin loaded Phycocyanin nanosponges (Cur-PC-NS) formulation is optimized and characterized. The formulation factors like drug polymer ratio, Aqueous/ Organic (A/O) phase ratio, concentrations of surfactant, Sonication &amp; stirring time were considered as function excipient have shown different response values in aspects of Particle Size (PS), Zeta Potential (ZP), % of entrapment efficiency (EE%) &amp; Loading capacity (LC%). In our findings F8 formulated nanosponges got 121.9nm particle size; -25.1mV zeta potential; 84.98% of Entrapment efficiency &amp; 52.92% of loading capacity. Thus exhibited change in A/O phase ratio, surfactant concentration &amp; Sonication time are 5:1, 0.5%, 1 hour respectively which have great impact on PS, EE% &amp; LC%. We conclude that factor and its positive impact on response have to be taken in concern and utilized; we can develop better sustain release curcumin loaded phycocyanin nanosponges

A new strategy for the preparation of core-shell MOF/Polymer composite material as the mixed-mode stationary phase for hydrophilic interaction/ reversed-phase chromatography

A facile method for efficient synthesis of core-shell composite material was proposed. In this method, the silica microspheres were co-modified with metal organic framework (MOF-235) and polyethylene glycol polymer (PEG) and used as mixed-mode stationary phase (MOF-235@PEG@silica) for high-performance liquid chromatography. Elemental analysis, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and Brunauer-Emmett-Teller etc. methods were used to investigate the properties of the core-shell composite material. The MOF-235@PEG@silica stationary phase showed flexible selectivity for the separation of both hydrophilic and hydrophobic compounds especially for the separation of nine alkaloids, which showed superior hydrophilic separation performance than previous MOF-based composite stationary phases. Some factors including the pH of buffer salt, the ratio of organic phase and water phase in the mobile phase have been investigated, suggesting that the chromatographic retention mechanism of the column was a mixed mode of hydrophilic and reversed phase. The composite material also showed excellent chromatographic repeatability with the RSDs of the retention time found to be 0.2%–0.6% (n = 10) and the standard addition test in the actual sample proved that it can be used for practical sample analysis. In short, it provided a general way for preparing MOFs-based composites as mixed-mode chromatographic stationary phases, and changed the current status of MOF-based composite materials as single mode chromatographic stationary phases.

Tailoring hydrophobic deep eutectic solvent for selective lithium recovery from the mother liquor of Li2CO3

• HDES synthesized by oleic acid and tetrabutyl ammonium chloride are more environmentally benign co-extractant. • The green synergic system TBP-HDES showed high lithium selectivity extraction. • The extraction mechanism were mainly cation exchange and Li + coordination. Recovering Li + from the mother liquor obtained during the process of Li 2 CO 3 production has been considered as a promising solution to the shortage of lithium resources. However, as the mother liquor is a complex saline system with high concentration of Li + (1.42 g/L) and a large amount of Na + (55.62 g/L), there is no competent method to carry out for the effective utilization of Li + . This work reports a class of hydrophobic deep eutectic solvents (HDESs) formed by tetrabutylammonium chloride (TBAC) and oleic acid (OA), which is a novel co-extraction reagent for Li + extraction. In addition, tributyl phosphate (TBP) is used as extractant and ammonia is applied to regulate pH. TBAC/3OA showed the highest extraction efficiency in single extraction (76.8%) with the ammonia concentration, the volume ratio of organic phase and aqueous phase (O/A phase ratio), and volume fraction of HDES as 1.5 mol/L, 1, and 30%, respectively. Mechanism studies through the UV–vis and FT-IR proved that cation exchange between Li + and HDES, and Li + coordination was the dominant force in the separation process. The complexing ability of P = O in TBP led to the selective extraction of Li + . The reusability experiments of organic phase demonstrated that the extraction efficiency was still above 60% after five cycles, indicating the favorable stability of the extraction system. Finally, the separation factor ( β Li/Na ) of Li/Na in the mother liquor was 20.5, indicating that the TBP-HDES system has the capability to selectively extract Li + with high Na/Li ratio. This will help to design possible green HDES for lithium recovery.

Salicylate UV-Filters in Sunscreen Formulations Compromise the Preservative System Efficacy against Pseudomonas aeruginosa and Burkholderia cepacia

Contamination of personal-care products are a serious health concern and therefore, preservative solutions are necessary for the costumers’ safety. High sun protection factor (SPF) sunscreen formulations are known to be difficult to preserve, due to their high ratio of organic phase containing the UV-filters. Salicylate esters such as octyl salicylate (OS) and homosalate (HS) are among the most common UV-filters currently used in the market, and can undergo hydrolysis by esterase molecules produced by contaminant microorganisms. The hydrolysis product, salicylic acid (SA) can be assimilated by certain bacteria that contain the chorismate pathway, in which its final product is pyochelin, an iron-chelating siderophore. Here, we show that OS and HS can compromise the preservative efficacy against two pathogenic important bacteria, Pseudomonas aeruginosa and Burkholderia cepacia. Challenge tests of formulations containing the UV-filters demonstrated that only bacteria with the chorismate pathway failed to be eradicated by the preservation system. mRNA expression levels of the bacterial pchD gene, which metabolizes SA to produce pyochelin, indicate a significant increase that was in correlation with increasing concentrations of both OS and HS. These data suggest that certain UV-filters can provide a source for bacterial resistance against common preservatives in sunscreen formulations.