Surfactant-Mediated Cloud Point Extractions: An Environmentally Benign Alternative Separation Approach

The efficiency of micellar solubilization of naphthalene from aqueous solutions using rhamnolipid as a biological surfactant according to NMR diffusometry

The micellar solubilization of naphthalene from its saturated aqueous solutions using the biosurfactant rhamnolipid was studied. Using the NMR diffusion method, selective measurements of the self-diffusion coefficients of molecules of all components of the solution-naphthalene, rhamnolipid, and water-were carried out at various rhamnolipid concentrations from 0.06 to 100 g/L. Based on the results of diffusometry, the distribution of naphthalene molecules between the states free in solution and states bound by micelles was found. With an increase in the concentration of rhamnolipids, the proportion of bound naphthalene molecules increases from 50% at CRL = 2 g/L to 100% at CRL ≥ 50 g/L. The micelle-water partition coefficient Km and the molar solubilization ratio MSR were calculated.

Recent developments in nanoemulsions against spoilage in cold-stored fish: A review

Nanoemulsion-based technology is developing rapidly in the food industry, especially in the design of delivery systems for bioactive compounds. This review presents an in-depth understanding of the composition, function, antibacterial mechanism and successful application of nanoemulsions as preservative agents against fish spoilage. The results showed that the inclusion of bioactive substances in the food-grade nanoemulsions encapsulation system could improve its stability, control its release, inhibit the microbial growth and reproduction through a variety of targets. These nanoemulsions can inhibit fish spoilage via reducing microbial load and retarding the oxidation of proteins and lipids, thereby maintaining quality attributes of fish. In addition, nanoemulsions could be coupled with vacuum package for enhancing microbial destruction, retaining nutritional value and extending the shelf-life of fish. Accordingly, nanoemulsions are suggested as a promising strategy to inhibit fish spoilage.

Rhamnolipid Biosurfactant: Use for the Removal of Phenol from Aqueous Solutions by Micellar Solubilization

Selective measurements of the self-diffusion coefficients of molecules of the biological surfactant rhamnolipid (RL) in individual aqueous solutions and in solutions with phenol as a solubilizate were carried out by nuclear magnetic resonance (NMR) diffusometry. Based on the obtained results, the solubilization characteristics of RLs were calculated. They are the fraction of solubilized phenol molecules, the phenol micelle-water distribution coefficient, the molar solubilization coefficient, the hydrodynamic radii of RL monomers and micelles, the aggregation numbers of micelles, and the solubilization capacity of micelles. Fraction of the solubilized phenol molecules increases and approaches 80-90% with increasing RL concentration. The solubilization capacity of the micelles increases from several units to 102 with an increase in both the concentration of RLs and the concentration of phenol in solution.

Analysis of bioactive compounds in cinnamon leaves and preparation of nanoemulsion and byproducts for improving Parkinson's disease in rats

Introduction

Cinnamomum osmophloeum Kanehira (C. osmophloeum), a broad-leaved tree species of Taiwan, contains phenolic acids, flavonoids, and phenylpropanoids such as cinnamaldehyde and cinnamic acid in leaves. Many reports have shown that the cinnamon leaf extract possesses anti-inflammatory, hypoglycemic, hypolipidemic and neuroprotective functions. This study aims to analyze bioactive compounds in C. osmophloeum (cinnamon leaves) by UPLC-MS/MS and prepare hydrosol, cinnamon leaf extract and cinnamon leaf nanoemulsion for comparison in improving Parkinson's disease (PD) in rats.

Methods

After extraction and determination of total phenolic and total flavonoid contents, cinnamaldehyde and the other bioactive compounds were analyzed in cinnamon leaves and hydrosol by UPLC-MS/MS. Cinnamon leaf nanoemulsion was prepared by mixing a suitable proportion of cinnamon leaf extract, soybean oil, lecithin, Tween 80 and deionized water, followed by characterization of particle size and polydispersity index by dynamic light scattering analyzer, particle size and shape by transmission electron microscope, encapsulation efficiency, as well as storage and heating stability. Fifty-six male Sprague-Dawley rats aged 8 weeks were divided into seven groups with group 1 as control (sunflower oil) and group 2 as induction (2 mg/kg bw rotenone in sunflower oil plus 10 mL/kg bw saline), while the other groups including rotenone injection (2 mg/kg bw) followed by high-dose of 60 mg/kg bw (group 3) or low-dose of 20 mg/kg bw (group 4) for tube feeding of cinnamon leaf extract or cinnamon leaf nanoemulsion at the same doses (groups 5 and 6) every day for 5 weeks as well as group 7 with rotenone plus hydrosol containing 0.5 g cinnamon leaf powder at a dose of 10 mL/kg bw. Biochemical analysis of brain tissue (striatum and midbrain) was done to determine dopamine, α-synuclein, tyrosine hydroxylase, superoxide dismutase, catalase, glutathione peroxidase and malondialdehyde contents by using commercial kits, while catalepsy performed by bar test.

Results and discussion

An extraction solvent of 80% ethanol was found to be the most optimal with a high yield of 15 bioactive compounds being obtained following UPLC analysis. A triple quadrupole tandem mass spectrometer with electrospray ionization mode was used for identification and quantitation, with cinnamaldehyde present at the highest amount (17985.2 µg/g). The cinnamon leaf nanoemulsion was successfully prepared with the mean particle size, zeta potential, polydispersity index and encapsulation efficiency being 30.1 nm, -43.1 mV, 0.149 and 91.6%, respectively. A high stability of cinnamon leaf nanoemulsion was shown over a 90-day storage period at 4 and heating at 100 for 2 h. Animal experiments revealed that the treatments of cinnamon leaf extract, nanoemulsion and hydrosol increased the dopamine contents from 17.08% to 49.39% and tyrosine hydroxylase levels from 17.07% to 25.59%, while reduced the α-synuclein levels from 17.56% to 15.95% in the striatum of rats. Additionally, in the midbrain of rats, an elevation of activities of superoxide dismutase (6.69-16.82%), catalase (8.56-16.94%), and glutathione peroxidase (2.09-16.94%) was shown, while the malondialdehyde content declined by 15.47-22.47%. Comparatively, the high-dose nanoemulsion exerted the most pronounced effect in improving PD in rats and may be a promising candidate for the development of health food or botanic drug.

Nanoparticulate pollutants in the environment: Analytical methods, formation, and transformation

The wide application of nanomaterials and plastic products generates a substantial number of nanoparticulate pollutants in the environment. Nanoparticulate pollutants are quite different from their bulk counterparts because of their unique physicochemical properties, which may pose a threat to environmental organisms and human beings. To accurately predict the environmental risks of nanoparticulate pollutants, great efforts have been devoted to developing reliable methods to define their occurrence and track their fate and transformation in the environment. Herein, we summarized representative studies on the preconcentration, separation, formation, and transformation of nanoparticulate pollutants in environmental samples. Finally, some perspectives on future research directions are proposed.

Innovative approaches in cloud-point extraction

Cloud-point extraction (CPE) is a pre-treatment technique for the extraction and preconcentration of different chemical compounds, such as metal ions, pesticides, drugs, phenols, vitamins etc., from various samples. CPE is based on the phenomenon of two phases (micellar and aqueous) forming after the heating of an aqueous isotropic solution of a non-ionic or zwitterionic surfactant above the cloud-point temperature. If analytes are added to the surfactant solution under suitable conditions, they should be extracted into the micellar phase, also called the surfactant-rich phase. Recently, the traditional CPE procedure is being increasingly replaced by improved CPE procedures. In this study, recent advances in CPE over the last three years (2020 - 2022), including the application of various innovative approaches, are reviewed. In addition to the basic principle of CPE, alternative extraction media in CPE, CPE supported by various auxiliary energies, a different modified CPE procedure and the use nanomaterials and solid-phase extraction in combination with CPE are presented and discussed. Finally, some future trends for improved CPE are presented.

Preparation and insecticidal performance of sustained-release cinnamon essential oil microemulsion

BACKGROUND

To improve the utilization rate of cinnamon essential oil and compensate for the shortcomings of its easy decomposition and oxidation, the microemulsion of cinnamon essential oil was prepared using Tween 80 and anhydrous ethanol as surfactant and cosurfactant, respectively. The effects of the surfactant type, K_m value, preparation temperature and aqueous pH on the quality of the microemulsion were studied via a pseudo-ternary phase diagram. The slow-release performance of cinnamon essential oil microemulsion and the control performance of the insect repellent package on the rice weevil were characterized.

RESULTS

The results showed that, when Tween 80 was used as a surfactant and anhydrous ethanol was used as a cosurfactant, the K_m value was 3:1, preparation temperature was 40 °C, aqueous pH was 5 and prepared cinnamon essential oil microemulsion was of the O/W type. The microemulsion had strong stability and a 81.5-nm concentrated particle size distribution, and possessed excellent embedding and sustained-release effects. The prepared insect repellent active package prolongs the use time and the effect of cinnamon essential oil. The repellent rate of the rice weevil was as high as 100% after 48 h, and the contact mortality and fumigation mortality rates of the rice weevil also reached 96.67% and 86.67%, respectively, after 96 h.

CONCLUSION

The prepared cinnamon essential oil microemulsion and active packaging had a good sustained-release effect. © 2021 Society of Chemical Industry.

Cloud point extraction associated with differential pulse voltammetry: preconcentration and determination of trace uranyl in natural water

A procedure for the electroanalytical determination of uranyl ions pre-concentrated from natural water by cloud point extraction (CPE) is developed in this study.

Successive preconcentration and mechanistic investigation of Au(iii), Pd(ii), Pt(iv) and Rh(iii) via cloud point extraction using a functionalised ionic liquid

This study proposes the efficient separation of Au(iii)/Pd(ii)/Pt(iv)/Rh(iii) through the 2-mercaptobenzothiazole-functionalised ionic liquid ([C6mim][2MBT]) using a cloud point extraction system.

Nanomicellar Extraction of Polyphenols-Methodology and Applications Review

The selection of the appropriate extraction method is crucial, especially for the receiving of active substances from plant material. The extraction using supercritical liquids and micellar-mediated extraction (MME) is the most advantageous among the alternative methods to classical solid-liquid extraction. However, the latter seems to be the best solution when the desired actives are polar. The following article presents a comprehensive review of the micellar-mediated extraction method in the last decade. The theoretical principle of the process was also refreshed and the current state of knowledge on the applications for analytical and manufacturing purposes was summarized.

Silver Nanoparticles Functionalized with Sodium Mercaptoethane Sulfonate to Remove Copper from Water by the Formation of a Micellar Phase

This work presents a novel procedure for the removal of Cu2+ from water, an essential element in human nutrition considered toxic in high concentrations, based on a microextraction technique involving the formation of a micellar phase. To achieve the total elimination of copper from aqueous samples, a Cu2+-complexing reagent based on silver nanoparticles functionalized with sodium mercaptoethane sulfonate (AgNPs@MESNa) was used. The complex formed by Cu2+ and the reagent was extracted into a micellar microphase formed by Triton X-114, a harmless surfactant. Volumes of 200 µL of the 10−4 mol L−1 suspension of AgNPs@MESNa and 100 µL of a solution of Triton X-114 at 30% m/m were employed to successfully remove 10 mg L−1 of Cu from 20 mL of water samples. The time and temperature needed to achieve 100% microextraction efficiency were 10 min and 40 °C, respectively. The procedure is considered environmentally friendly due to the low volume of the extracting phase and the simple experimental conditions that achieve total removal of Cu2+ from water samples.

Trimeric Cationic Surfactant Coacervation as a Versatile Approach for Removing Organic Pollutants

A versatile method to remove a broad spectrum of dye pollutants from wastewater rapidly and efficiently is highly desirable. Here, we report that the complex coacervation of cationic trimeric imine-based surfactants (TISn) with negatively charged hydrolyzed polyacrylamide (HPAM) can be used for this purpose. The coacervation occurs in a wide concentration and composition range and requires the HPAM and TISn concentrations as low as 0.1 g/L and 0.1 mM, respectively. Dye effluents treated by trimeric surfactants and HPAM complete phase separation within 30 s under turbulent conditions, which generates an exceedingly small volume fraction (0.4%) of viscoelastic coacervate and a clear supernatant with a dye removal efficiency of up to 99.9% for anionic and neutral dyes in dosages of up to 120 mg/L. Crowded molecular arrangement and thick framework in coacervate are responsible for the rapid phase separation rate and low volume fraction. The trimeric imine surfactant/polymer coacervation provides a simple, effective, and sustainable approach for the rapid removal of dyes and other organic pollutants.

Insights into the behavior of ethylene oxide-1,2-epoxybutane diblock copolymers in water as a function of temperature and the presence of colloidal silica

HYPOTHESIS

Nonionic surfactants have been widely used for many consumer products and industrial processes, and their applications often involve temperature-cycling across cloud point temperature (T_cloud). To explore the behavior of nonionic surfactants across T_cloud and when mixed with colloidal silica at a very dilute concentration around 0.1 wt%, a series of 1,2-epoxybutane-capped alcohol ethoxylates (BAEs) with various cloud points is used as a model system.

EXPERIMENTS

BAEs with cloud points from 15 to 64 °C were successfully prepared by varying the lengths of 1,2-epoxybutane (BO) and ethylene oxide (EO) blocks and their phase behavior across T_cloud was studied using nuclear magnetic resonance spectroscopy (NMR), dynamic light scattering (DLS) and differential scanning calorimetry (DSC).

FINDINGS

In the absence of silica, the NMR signals are not greatly affected by the cloud point transition, but both the water and surfactant exhibit a decrease in spin-spin relaxation time once the temperature reaches the T_cloud. In the presence of silica, the NMR spectra indicate significantly reduced mobility of the EO portion relative to the alkyl and BO segments. Furthermore, our results suggest that the BAE surfactants are not fractionally clouding out or precipitating with a portion of the compositional distribution during the cloud point transition.

Determination of Antidepressants in Human Plasma by Modified Cloud-Point Extraction Coupled with Mass Spectrometry

Cloud-point extraction (CPE) is rarely combined with liquid chromatography coupled to mass spectrometry (LC-MS) in drug determination due to the matrix effect (ME). However, we have recently shown that ME is not a limiting factor in CPE. Low extraction efficiency may be improved by salt addition, but none of the salts used in CPE are suitable for LC-MS. It is the first time that the influences of a volatile salt-ammonium acetate (AA)-on the CPE extraction efficiency and ME have been studied. Our modification of CPE included also the use of ethanol instead of acetonitrile to reduce the sample viscosity and make the method more environmentally friendly. We developed and validated CPE-LC-MS for the simultaneous determination of 21 antidepressants in plasma that can be useful for clinical and forensic toxicology. The selected parameters included Triton X-114 concentration (1.5 and 6%, w/v), concentration of AA (0, 10, 20 and 30%, w/v), and pH (3.5, 6.8 and 10.2). The addition of 10% of AA increased recovery twice. For 20 and 30% (w/v) of AA, three phases were formed that prolonged the extraction process. The developed CPE method (6% Triton X-114, 10% AA, pH 10.2) was successfully validated through LC-MS/MS simultaneous determination of 21 antidepressants in human plasma. The linearity was in the range of 10-750 ng/mL (r2 > 0.990).

Micelles of Oxyethylated Isononylphenols in Aqueous Solutions and Hydrophilic-Lipophilic Balance

We have measured the self-diffusion coefficients and calculated the effective hydrodynamic radii of micelles of ethoxylated isononylphenols in aqueous solutions in the presence of sodium chloride, as well as in their binary mutual mixtures, when approaching cloudy conditions. These cloudy conditions were created by an increase in temperature, a change in the concentration of an electrolyte in the solution, or a mutual ratio of neonols in their binary mixtures. The results are discussed within the concept of the hydrophilic-lipophilic balance.

Natural TiO2-Nanoparticles in Soils: A Review on Current and Potential Extraction Methods

The monitoring of anthropogenic TiO2-nanoparticles in soils is challenged by the knowledge gap on their characteristics of the large natural TiO2-nanoparticle pool. Currently, no efficient method is available for characterizing natural TiO2-nanoparticles in soils without an extraction procedure. Considering the reported diversity of extraction methods, the following article reviews and discusses their potential for TiO2 from soils, focusing on the selectivity and the applicability to complex samples. It is imperative to develop a preparative step reducing analytical interferences and producing a stable colloidal dispersion. It is suggested that an oxidative treatment, followed by alkaline conditioning and the application of dispersive agents, achieve such task. This enables the further separation and characterization through size or surface-based separation (i.e., hydrodynamic fractionation methods, filtration or sequential centrifugation). Meanwhile, cloud point extraction, gel electrophoresis, and electrophoretic deposition have been studied on various nanoparticles but not on TiO2-nanoparticles. Furthermore, industrially applied methods in, for example, kaolin processing (flotation and flocculation) are interesting but require further improvements on terms of selectivity and applicability to soil samples. Overall, none of the current extraction methods is sufficient toward TiO2; however, further optimization or combination of orthogonal techniques could help reaching a fair selectivity toward TiO2.

Looking at Silver-Based Nanoparticles in Environmental Water Samples: Repetitive Cloud Point Extraction Bridges Gaps in Electron Microscopy for Naturally Occurring Nanoparticles

The growing use of silver-based nanoparticles (Ag-b-NPs) in everyday products goes hand in hand with their release into the environment, resulting in ng L^-1 traces in natural water bodies. In order to assess their fate, possible transformations and ecotoxicology-essential information to proper risk assessment-particle size, shape, and chemical composition have to be determined. Transmission electron microscopy coupled with energy dispersive X-ray spectroscopy (TEM-EDX) is a powerful tool for determining these particle characteristics, but it requires high particle concentrations in order to produce statistically reliable results. In this study, we will present the extraction of Ag-b-NPs at environmentally relevant concentrations down to 5 ng L^-1 from artificial as well as environmental water samples via cloud point extraction on a repetitive basis. The combination with an on-grid centrifugation technique ensures an efficient concentration and deposition of the extracted particles onto the TEM grid for subsequent TEM-EDX measurements. Furthermore, electron microscopy investigations were supplemented by single particle inductively coupled plasma mass spectrometry (sp-ICP-MS) measurements. Ag-b-NPs were successfully visualized and characterized at environmentally relevant concentrations of 5 ng L^-1 with TEM-EDX and sp-ICP-MS measurements. Their size, shape, and chemical composition were not affected by the sample preparation.

Rapid Micelle-Mediated Size-Controlled Fabrication of Calcium Sulfate Nanorods Using Silver Nanoparticles

Calcium sulfate nanorods (CS-NRs) are valuable materials utilized in various applications, particularly in the medical field. In this work, the size-controlled synthesis of CS-NRs was carried out on the basis of the micelle-mediated phase separation phenomenon. A nonionic surfactant, Triton X-114, was employed for the thermoresponsive phase separation of a homogeneous solution to a surfactant-rich phase. Whereas each specific ion, Ca²⁺ and SO₄^2-, was difficult to individually extract when present at concentrations less than their equilibrium concentration (solubility product constant, K_sp), the synthesized CS microrods (CS-μRs) were extracted into the surfactant-rich phase (enrichment factor = ca. 50). The presence of nitric acid increased the size of the materials up to 6707 ± 3488 nm on the long side and 87 ± 37 nm on the short side. The addition of silver nanoparticles (Ag-NPs) to the reaction mixture led to the formation of much smaller products, i.e., uniform CS-NRs whose sizes were in the range of 89 ± 15 nm (long side) and 25 ± 4 nm (short side). The size of the extracted Ag-NPs and CS-NRs decreased with an increase in added Ag-NP concentration until their microscopic observation became difficult. The factors (such as additive concentration, pH, temperature) affecting size control were evaluated.

Adsorption onto MWCNTs Coupled with Cloud Point Extraction for Dye Removal from Aqueous Solutions: Optimization by Experimental Design

AIMS

The main aim of the study was to examine the feasibility and benefits of adsorption onto multi-walled carbon nanotubes (MWCNTs) coupled with cloud point extraction (CPE) for the removal of Rhodamine B (RB) from aqueous solutions.

BACKGROUND

MWCNTs offer the particular features of the ideal adsorbents for the organic dyes such as hollow tubular structure and specific surface area. Nevertheless, they suffer from the drawbacks of low dispersion in the aqueous solutions and separation inconvenience from the media. Cloud point extraction, combined with the adsorption onto MWCNTs can be a promising method to overcome the problems.

OBJECTIVE

In the study, adsorption onto MWCNTs coupled with CPE was applied for RB removal from aqueous solutions. The process was optimized by the response surface modeling method. Moreover, the applicability of the proposed method in the real sample analyses was investigated.

METHODS

MWCNTs were used as adsorbent and Triton X-100 (TX-100) as the nonionic surfactant for CPE process. The experiments were carried out based on a Box-Behnken design (BBD) with the input variables of MWCNTs dosage (0.6-1.2 mg), solution pH (3-9), clouding time (20-40 min) and TX-100 concentration (10-20 v/v%) using 5 mg L-1 RB solutions.

RESULT

Regression analyses resulted in a statistically significant quadratic model (R2=0.9718, F=24.96, p<0.0001) by which the optimum levels of the variables were predicted as: MWCNTs dosage of 0.7 mg, pH=3, clouding time of 39.9 minutes and TX-100 concentration of 19.91% (v/v). The predicted conditions were experimentally validated by achieving an RB removal of 94.24%.

CONCLUSION

Based on the results, the combination of the environmentally friendly technique of CPE with adsorption onto MWCNTs allows the efficient removal of RB from water samples and the method can be effectively optimized by the response surface modeling.

Recovery and purification of cellulolytic enzymes from Aspergillus fumigatus CCT 7873 using an aqueous two-phase micellar system

Purpose

In this study, an aqueous two-phase micellar system (ATPMS), formed by the non-ionic surfactant Triton X-114, was used to investigate the partitioning of cellulolytic enzymes produced by the filamentous fungus Aspergillus fumigatus CCT 7873.

Methods

Performance of the ATPMS on the partitioning of CMCase (activity on carboxymethyl cellulose) and FPase (activity on filter paper) was investigated by varying the temperature (35, 40, 45, 50, 55, 60, and 65 °C), enzyme crude extract concentration (20, 40, 60, and 80% w/w), and Triton X-114 concentration (2, 4, 6, and 8% w/w) and by adding different inorganic salts (NaCl, CaCl2, MgSO4, and MnSO4) in the system.

Results

An ATPMS formed with 8% (w/w) Triton X-114 and 40% (w/w) enzymatic crude extract at a system temperature of 55 °C was most favorable for partitioning the tested enzymes. Under these conditions, a purification factor for CMCase and FPase of 10.89 and 0.65 was reached, respectively. The addition of inorganic salts changed the distribution of enzymes. Of these, CaCl2 contributed to a higher distribution coefficient (50.0), whereas for FPase, the presence of MnSO4 in the system improved the purification factor to 3.94.

Conclusion

The highest values obtained for the yield and purification factors demonstrate that ATPMS is an interesting option for recovering and purifying cellulolytic enzymes.

Twenty years of supramolecular solvents in sample preparation for chromatography: achievements and challenges ahead

Supramolecular solvents (SUPRAS) have progressively become a suitable alternative to organic solvents for sample preparation in chromatographic analysis. The inherent properties of these nanostructured solvents (e.g. different polarity microenvironments, multiple binding sites, possibility of tailoring their properties, etc.) offer multiple opportunities for the development of innovative sample treatment platforms not approachable by conventional solvents. In this review, major achievements attained in the combination SUPRAS-chromatography in the last 20 years as well as the challenges that should be addressed in the near future are critically discussed. Among achievements, particular attention is paid to the theoretical and practical knowledge gained that has helped make substantial progress in the area. In this respect, advances in the understanding of the mechanisms involved in SUPRAS formation and SUPRAS-solute interactions driving extractions are discussed, with a view to the setting up of knowledge-based extraction procedures. Likewise, the strategies followed to improve the compatibility of SUPRAS extracts with liquid and gas chromatography and adapt SUPRAS-based extractions to different formats are presented. Ongoing efforts to apply SUPRAS in multicomponent extractions and synthesize tailored SUPRAS for the development of innovative sample treatments are highlighted. Among challenges identified, discussion is focused on the automation of SUPRAS-based sample treatment and the elucidation of SUPRAS nanostructures, which are considered essential for their acceptance in routine labs and the design of tailored SUPRAS with programmed functions. Graphical abstract.

Cloud point extraction coupled with back extraction: a green methodology in analytical chemistry

Recently, cloud point extraction (CPE) coupled with back extraction (BE) has been suggested as a promising alternative to liquid-liquid extraction. In CPE, non-ionic surfactants in aqueous solutions form micelles and the solution becomes turbid when heated to the cloud point temperature. Microwave- or ultrasonic-assisted BE can be performed after CPE and before injection of the sample for instrumental analysis by ultraviolet-visible spectroscopy, high-performance liquid chromatography, gas chromatography, gas chromatography-mass spectrometry, or liquid chromatography-mass spectrometry. This article reviews selected published scientific research on the application of CPE-BE to the determination of alkaloids, drugs and organophosphorus compounds from several complex matrices. This method could be scaled-up for use in forensic science.

Easy Removal of Methylparaben and Propylparaben from Aqueous Solution Using Nonionic Micellar System

This study aimed to investigate the simultaneous removal of methylparaben (MePB) and propylparaben (PrPB) from effluents (each one at 16 mg/L) using a nonionic micellar system containing Triton X-114. Response surface methodology (RSM) has been carried out. Extraction results using nonionic surfactant two-phase system were considered as a function of surfactant concentration and temperature variation. Four responses were investigated: MePB and PrPB extraction yield (E), solute (Xs,w) and surfactant (Xsf,w) concentrations in the aqueous phase and the volume fraction of micellar phase (ϕC) at equilibrium. Very high extraction efficiencies (99 % for PrPB and 84 % for MePB) were achieved at optimal conditions. Thereby, the amounts of PrPB and MePB were reduced 80 and 5 times, respectively. The extraction improvement using sodium sulfate was also shown. Finally, the solute stripping from micellar phase by pH change was proved.

Temperature-responsive extraction of violacein using a tuneable anionic surfactant-based system

A tuneable and thermoresponsive ionic system is applied to the extraction and cloud-point separation of violacein from biomass.

A one-pot, isothermal DNA sample preparation and amplification platform utilizing aqueous two-phase systems

Infectious diseases remain one of the major causes of death worldwide in developing countries. While screening via conventional polymerase chain reaction (PCR) is the gold standard in laboratory testing, its limited applications at the point-of-care have prompted the development of more portable nucleic acid detection systems. These include isothermal DNA amplification techniques, which are less equipment-intensive than PCR. Unfortunately, these techniques still require extensive sample preparation, limiting user accessibility. In this study, we introduce a novel system that combines thermophilic helicase-dependent amplification (tHDA) with a Triton X-100 micellar aqueous two-phase system (ATPS) to achieve cell lysis, lysate processing, and enhanced nucleic acid amplification in a simple, one-step process. The combined one-pot system was able to amplify and detect a target gene from whole-cell samples containing as low as 10² cfu/mL, and is the first known application of ATPSs to isothermal DNA amplification. This system's ease-of-use and sensitivity underlie its potential as a point-of-care diagnostic platform to detect for infectious diseases. Graphical abstract ᅟ.