Cloud Point Extraction Method Research Articles

Enhanced Extraction of Tanshinones from Salvia miltiorrhiza Using Natural-Surfactant-Based Cloud Point Extraction

Salvia miltiorrhiza (SM) contains the tanshinones, a compound with various pharmacological effects, and has been extensively studied as a pharmaceutical material. However, conventional methods for extracting tanshinones face challenges such as environmental hazards and high cost. In this study, we aimed to effectively extract tanshinones from SM using cloud point extraction (CPE) with lecithin, a natural surfactant. By optimizing various extraction conditions including the solid-to-liquid ratio, lecithin concentration, NaCl concentration, pH, and equilibrium temperature, the optimal extraction efficiency was achieved using 20 mL of solvent per 1 g of sample, 3% lecithin (w/v), 2% NaCl (w/v), pH 6, and room temperature (25 ± 2 °C). The CPE method, which minimizes the use of organic solvent and is eco-friendly, demonstrated improvements in extraction efficiency, with a 4.55% increase for dihydrotanshinone I, 8.32% for cryptotanshinone, 15.77% for tanshinone I, and 6.81% for tanshinone IIA compared to the conventional water extraction method. These results suggest that CPE is a promising, environmentally friendly, and efficient approach for extracting hydrophobic components from pharmacologically active materials such as SM, with potential applications across various fields of natural product extraction.

Spectrophotometric determination of zinc in blood and food samples using an air-assisted rapid synergistic-cloud point extraction method based on deep eutectic solvents

At room temperature, an air-assisted rapid synergistic cloud point extraction (AA-RS-CPE) method based on deep eutectic solvent (DES) was presented to determine Zn (II) traces in various samples. Nonanoic acid and L-menthol formed the synergistic reagent (DES) in a 2:1 mole ratio to reduce both time and cloud point temperature. Air cycles were used to maximize recovery and accelerate cloudy solution formation. The 4,4-dimethyl-2,6-dioxo-N-phenylcyclohexanecarbothioamide (DDPCCTA) and TritonX-100 were used as ligand and surfactant, respectively. The validation parameters, including the calibration curve linearity (0.2-900µgL-1), the limit of detection (LOD = 0.10µgL-1), the enhancement factor (EF = 120), and the preconcentration factor (PE = 100), were calculated. Additionally, the accuracy of the AA-RS-DES-CPE approach was proved by two certified reference materials (CRMs). Finally, the three greenness tools, the Blue Applicability Grade Index (BAGI), the Sample Preparation Metric of Sustainability (SPMS), and the Analytical Greenness Metric for Sample Preparation (AGREEprep), were used to evaluate the environmental sustainability values, health hazards, and applicability of this method. This approach was improved to be safer and more environmentally friendly than existing methods, with high application potential.

Innovative utilization of olive mill wastewater phenolics extracted by lecithin: spray-dried powders in cake formulations

In the present study, the olive mill wastewater (OMW) phenolics were extracted with soy lecithin using the cloud point extraction method, and this enriched lecithin (OMW-L) was converted into spray-dried powders using maltodextrin (MD) and whey protein concentrate to be utilized as a dry food ingredient in a cake premix. The inlet temperature of 170 °C and a 3 mL/min feed flow rate yielded the highest powder yield (70.88 ± 2.12%) with a moisture content of 3.78 ± 0.03% when the mass ratio of lecithin to MD was 1:3 (w:w). The hydroxytyrosol and tyrosol contents of the powder were 42.60 ± 4.51 mg/100 g and 15.48 ± 2.50 mg/100 g, respectively. Vanillic acid, caffeic acid, 3-hydroxybenzoic acid, catechin, and rutin were also identified in the powders. The spray-dried OMW-L powder with a higher loading of polyphenols was then used in a cake premix, replacing 1% and 3% of wheat flour. This substitution significantly reduced the K value of the cake batter, as determined by rheological analyses. The addition of spray-dried OMW-L powder to the cake samples, particularly at higher concentrations (3%), influenced both crust and crumb color, causing changes in L*, a*, and b* values. The hardness values of the cake samples did not alter when blank or OMW-enriched lecithin powders were added; rather, the hardness value was influenced by the powder content. Overall, this research offers a different perspective on the use of OMW phenolics in food applications, especially in ready-to-use blends, and demonstrates the effects of the obtained spray-dried lecithin powders on batter rheology and cake characteristics.Graphical abstract

Cloud Point Extraction Method for Spectrophotometric Determination of 3-Aminophenol in Environmental Samples

Cloud Point Extraction Method for Spectrophotometric Determination of 3-Aminophenol in Environmental Samples

Evaluation of Lead Ion in the Wastewater of the Lifting and Treatment Stations Using ICP-MS and CPE Methods

To pre-concentrate trace amounts of lead before determining it by UV-vis spectrophotometer, a new method for micelle-mediated phase separation has been created. The process depends on the extraction of lead from iodine media using Triton X-114 in the cloud point extraction method without the need for any chelating agents, where the optimal conditions for the method were achieved, which temperature 50 °C, pH 4, and 30 mmol L−1 concentration of KI, 0.3 mL of 2% (v/v) Triton X-114, and time of 10 min in the water bath. Linearity was followed between 1 and 16 µg/mL of lead concentration. The method's lead detection limit is 0.1 µg/mL and %RSD 3.633. Additionally, the interference impact of certain cations was evaluated. The proposed technique was successfully applied to determine the lead ion in the wastewater in ten different stations in the center and district of Al-Hur in Karbala City. The lead ion of the wastewater of the stations under study was also determined directly using inductively coupled plasma-mass spectrometry (ICP-MS) technology comparing its results with the new method and performing the statistical analysis of both methods. The p-value was less than 0.05, showing significant differences between both methods.

Rapid preconcentration and determination of Co (II) ions in aqueous medium using ultrasound assisted cloud point extraction method

A flame atomic absorption spectrophotometric technique was studied for the preconcentration and determination of of Co2+ ions in trace amounts after ultrasound enhanced enrichment of its 1-(2-pyridylazo)-2-naphthol (PAN) complexes by cloud point extraction. The Co2+ ions were firstly complexed with PAN molecules at pH 4 and the complex transferred to a surfactant (Tergitol NP-7) rich phase with a very small volume under ultrasound waves. The surfactant rich phase was separated and dissolved by 1 mL, 1.0 M HNO3 in ethanol prior to determination of Co2+ concentration by flame atomic absorption spectrophotometry. The optimization steps of ultrasound interaction time, solution pH and surfactant volumes were achieved by response surface methodology (RSM) which is a combination of statistical approaches. Sample volume, PAN concentration and and possible interfering ions were optimized conventionally. The Co2+ ions were extracted only in 150 s at pH 4 quantitatively under optimum conditions (˃95%). The accuracy and validity of developed UA-CPE was granted by employing a certified reference material wastewater UME CRM 1204. The technique was applied to wastewater and natural water with satisfactory results.

Aspirin Spectrophotometric Determination using Cloud Point Extraction and HPLC in Several Pharmaceuticals Sold in Iraqi Markets

In this work, a sensitive tandem cloud-point extraction (CPE) method with a solvation system was employed to detect aspirin in various pharmaceuticals. Aspirin, in a dilute acidic solution, formed a complex with Zn(II) ions ([Zn(II)-aspirin] complex), which was then extracted using two different surfactant systems - nonionic surfactant Triton X-100 and a mixture of surfactants (SDS-Tween 80). The extracted complex was subsequently determined using spectrophotometry at a wavelength of 293 nm for Triton X-100 and 231 nm for SDS-Tween 80. The parameters for extraction, including HCl and Zn(II) concentration, temperature, heating time, and solvent used to dissolve the cloud point layer, were thoroughly investigated. Highperformance liquid chromatography (HPLC) was used as the standard method to compare the quantitative analysis of the cloud-point extraction-onium system.

A novel in-syringe cloud point extraction method for the determination of cadmium and lead in human hair samples

Measurement of contaminant elements in biological samples requires time-consuming sample preparation. The proposed in-syringe cloud point extraction (IS-CPE) as a fast, easy, low-cost, and green method was successfully used to measure lead and cadmium in human hair samples.

Cloud Point Extraction Method for Separation and Preconcentration of Molybdenum and Zirconium Using Mixture of Surfactants from Natural Waters and their Determination by Spectrophotometry

Cloud Point Extraction Method for Separation and Preconcentration of Molybdenum and Zirconium Using Mixture of Surfactants from Natural Waters and their Determination by Spectrophotometry

Simultaneously HPLC Analysis of B1, B9 and B12 Vitamins at Trace Levels via Cloud Point Extraction

An enrichment and determination method based on liquid chromatographically analysis and cloud point extraction (CPE) has been developed for trace levels of B vitamins (B1, B9 and B12) in the proposed study. Vitamin molecules were drawn into the non-ionic surfactant phase of Polyethylene Glycol (PEG-6000) in the presence of pH 9.0 medium. The surfactant-rich phase separated by centrifugation and then dissolved with 700 µL of ethanol. The obtained ethanol phase was filtered by 0.45-micron filter prior to the HPLC analysis. All parameters affecting the CPE method such as pH, buffer volume, incubation time, surfactant and electrolyte concentration, solvent for the surfactant-rich phase and its amount have been individually studied and optimized step by step. After the optimization of all parameters of the CPE process, the detection limits of the developed method for B1, B9 and B12 vitamins were calculated as 1.42 ng mL-1, 7.14 ng mL-1 and 14.28 ng mL-1 , respectively. The linear working ranges for three vitamin molecules was obtained in the range of 5.0-500.0 ng mL-1. After CPE procedure, determination of vitamin molecules was carried out by using HPLC system with diode array detector(DAD) at 244 nm for vitamin B1, 285 nm for vitamin B9, and 361 nm for vitamin B12, respectively

Removal of Aluminum from Synthetic Rare Earth Leach Solution by Selective Complexation and Turbidity Point Extraction

During the leaching process of ion-adsorbed rare earth ores, large amounts of non-rare earth impurities such as aluminum and iron will be generated. This study selected glutamic acid as a complex agent to selectively calculate aluminum ions; then, added non-ionic surfactants and extract and separate aluminum ions from a rare earth solution using the cloud point extraction method. The effects of solution pH, reaction temperature, equilibration time, amount of glutamic acid, reaction time, and amount of Triton X-114 on aluminum extraction were investigated. The results showed that with a Mglu:MAl ratio of 3:1, a solution pH of 4.5, a constant temperature of 40 °C, and the addition of 10 mL Triton X-114 after 10 min of reaction time, the single extraction efficiency of aluminum ions reached 78.01%, and the extraction efficiency of rare earths was only 5.09% after 10 min of equilibration time. The reaction equation of glutamic acid with aluminum ions was determined, and the lowest extraction concentration of aluminum ions in the glutamic acid complexation extraction solution was found to be cAl = 0.045 ± 0.003 g/L, with a separation coefficient of β(Al/RE) = 66.15. This result indicated that the aluminum ions in the mixed solution could be effectively separated from the rare earth ions when using glutamic acid as a complexing agent in combination with the turbidity point extraction method.

Isolation of Polyphenols from Two Waste Streams of Clingstone Peach Canneries Utilizing the Cloud Point Extraction Method

This study aimed to assess the feasibility of employing cloud point extraction (CPE) as an efficient way of extracting polyphenols from peach waste (PW). Four distinct food-grade surfactants (Genapol X-080, PEG 8000, Tween 80, and lecithin) were evaluated at concentrations ranging from 2–10% w/v to determine the efficiency of the technique in two separate PW streams [i.e., lye peeling waste stream (LPWS) and total wastewater stream (TWS)]. Low amounts (2% w/v) of surfactants in a single-step CPE were found to result in less than ~61% polyphenol recovery in LPWS and less than ~69% polyphenol recovery in the TWS, necessitating additional extraction steps. In both PW streams, the single-step polyphenol recovery was improved by 25–67% utilizing a higher amount of surfactants (5–10% w/w), leading to a statistically significant figure (p < 0.05). The CPE procedure was conducted under optimal conditions, including a temperature of 65 °C, a sodium chloride concentration of 3% w/v, a pH level of 3.5, and a surfactant concentration of 5% w/v. The polyphenol recovery was efficient when the CPE procedure was conducted twice. Tween 80 proved to be the most efficient surfactant among the four tested surfactants, achieving recoveries above 98% in both PW streams. Under optimum extraction conditions, the total polyphenol content and antiradical activity of PW extracts were evaluated. The results showed statistically significant differences (p < 0.05) between the two PW streams, with the LPWS having approximately 12 times higher polyphenol content and being more potent, achieving ~64% antiradical activity. Using the LPWS instead of the TWS is a more cost-effective and feasible option for the industry. In addition, the considerable volume of the TWS makes it challenging to handle and demands a correspondingly major amount of surfactant. Considering that Tween 80 is a low-toxicity surfactant and that the CPE method is simple, fast, cost-effective, highly accurate, and selective, the extracted polyphenols from two PW streams could be exploited as natural antioxidants to be used directly in the food industry. These findings could have major implications for the manufacturing of sustainable and naturally-derived food additives.

Cloud point extraction of carbendazim fungicide from strawberry samples and amperometric detection with boron doped diamond

The cloud point extraction (Tergitol® surfactant) method was used for the first time to extract and preconcentrate the fungicide carbendazim (CBZ) from strawberry samples, while electrochemical detection (boron doped diamond electrode) in association with high performance liquid chromatography (HPLC-EC) was used for the determination of CBZ. The variables of bath temperature, ultrasonic stirring time, mass of NaCl and amount of surfactant were investigated using a 24 full factorial design. Limits of detection (LOD, S/N = 3) and quantification (LOQ) of 3.42 × 10−8 mol/L (or 6.54 µg/L) and 6.84 × 10−8 mol/L (or 13.1 µg/L), respectively, were obtained for the CPE processes, considering the value of the preconcentration factor obtained (9.12). The method was validated based on linearity, intra-day and inter-day recovery tests, accuracy and precision. The proposed method was applied to strawberry samples from local commercial establishments and different procedures for washing and sanitizing strawberry fruits were also evaluated.

Implementation of Cloud Point Extraction Using Surfactants in the Recovery of Polyphenols from Apricot Cannery Waste

The objective of this study was to investigate the feasibility of using Cloud Point Extraction (CPE) to isolate natural antioxidants (polyphenols) from apricot cannery waste (ACW). Four different food-grade surfactants (Genapol X-080, PEG 8000, Tween 80, and Lecithin) were tested at varying concentrations to evaluate the effectiveness of the technique. It was observed that low concentrations of surfactants in one-step CPE resulted in less than 65% polyphenol recovery, which necessitated further extraction steps. However, high concentrations of surfactants were found to significantly improve polyphenol extraction from ACW for all surfactants tested. Among the four surfactants, PEG 8000 was found to be the most effective in most circumstances; specifically, adding only 2% of the surfactant per step in a two-step CPE was enough to effectively extract polyphenols with recovery rates better than 99%. When 10% w/v of PEG 8000 was used, recoveries greater than 92% were obtained. Since PEG 8000 is a reagent with low toxicity and the CPE method is simple, rapid, cheap, sensitive, and selective, the extracted organic compounds from ACW can be used as natural antioxidants in food technology. This has important implications for the development of natural and sustainable food additives.

Quantitative separation of thorium from rare earth elements and uranium in a rare earth element sulfuric acid leachate using cloud point extraction

A new cloud point extraction (CPE) method was created for extracting and concentrating thorium from a sulfuric acid leachate of rare earth elements (REESL). The method employs P,P′-di(2-ethylhexyl) methanediphosphonic acid (H2DEH[MDP]) as a chelating agent that has a strong attraction for actinides. By using Triton X-100 as a non-ionic surfactant and cetyl trimethyl ammonium bromide (CTAB) as an ionic surfactant, thorium is quantitatively extracted (over 98%) into a small volume of the surfactant-rich phase through heating and centrifugation. The method is based on in situ bromine formation to improve phase separation at highly acidic pH values resulting from the leaching steps. The method yielded a preconcentration factor of 22 when tested on REESL. To our knowledge, it is the first paper dealing with the use of CPE to selectively separate Th(IV) from rare earth elements and U from mining leachates.

Determination of trace cobalt (II) in spices samples by ultrasonic assisted cloud point extraction with spectrophotometry

In this study, ultrasonic assisted cloud point extraction (UA-CPE) method was developed for the determination of Cobalt (II) (Co(II)) in spices. After extraction and preconcentration, the Co(II) contents of the samples were determined by UV–VIS. After complexing with Ponceau Xylidine (PX) and EDTA in the presence of cationic surfactant, CTAB at pH 4.0 with Britton–Robinson (BR) buffer, Co(II) ion was withdrawn the surfactant-rich phase of nonionic surfactant, Triton X-114 (TX-114). The concentrated surfactant-rich phase containing the analyte was diluted with ethanol to a volume of 1.0 mL and then analyzed by UV–VIS spectrophotometer. The various analytical parameters affecting the UA-CPE yield were investigated and optimized. Analytical data achieved after optimization: limits of detection (LOD) and: limits of quantification (LOQ) are 0.76 and 2.59 μg L−1, respectively; The calibration curve is rectilinear for Co(II) with changed calibration sensitivity in the range of 1–10 and 10-210 μg L−1. The precision (as RSD%) is 4.8. This optimized method was applied in the analysis of various spice samples.

Separation and Micro Determination of Zinc(II) and Cadmium(II) in Food Samples Using Cloud Point Extraction method

The cloud point extraction technique has become increasingly popular in recent years for trace metal separation and preconcentration. When heated to a specific temperature, cloud point extraction utilizes the property of nonionic surfactants in aqueous solutions to generate micelles and become turbid (so-called cloud point temperature). For analytical chemists, developing a simple and selective technology for the separation and determination of metals and medicinal drugs is a critical concern. Therefore, a sensitive, accurate, and green cloud point extraction (CPE) procedure was developed for the micro-determination of metal cations like zinc (II) and cadmium (II) in food samples. Triton X–114 and 1-(4-(Phenyldiazenyl) phenyl) azo naphthalene-2-ol (Sudan III) were used as extractants. Sudan III forms an ion-pair association complex with metal ions when the pH is 9. In the presence of 5 ppm zinc (II) or 4 ppm cadmium (II) in an aqueous solution, the maximum extraction efficiency should be achieved. In order to create Cloud Point Temperature (CPT) quantitatively, the extraction applications in this approach required heating at 85°C for 20 minutes. In this work, the impacts of different surfactants, pH, stoichiometry, and various organic reagents on interferences as well as spectrophotometric determination were explored. The linearity ranges of zinc (II) and cadmium (II) were 0.25-700 and 0.25-400 ppm, respectively. The results show low detection limits of 0.035 and 0.042 ppm for zinc (II) and cadmium (II), respectively. Also, the quantification limits for zinc (II) and cadmium (II) are 0.116 and 0.140 ppm, respectively.

Fate Determination and Characterization of Food Additive Silicon Dioxide and Titanium Dioxide in Commercial Foods.

Silicon dioxide (SiO2) and titanium dioxide (TiO2) are ones of the most widely used food additives as an anti-caking and a coloring agent, respectively, in the food industry. Understanding particle, aggregate, or ionic fates of two additives in commercial products is of importance to predict their potential toxicity. Triton X-114 (TX-114)-based cloud point extraction (CPE) methods for two additives were optimized in food matrices. Their particle or ionic fates in various commercial foods were determined by the CPE, and the physico-chemical properties of separated particles were further characterized. SiO2 and TiO2 were primarily present as particle forms without changes in constituent particle size, size distribution, and crystalline phase. The maximum solubilities of SiO2 and TiO2 were 5.5% and 0.9%, respectively, depending on food matrix type, supporting their major particle fates in complex food matrices. These findings will provide basic information about the fates and safety aspects of SiO2 and TiO2 additives in commercial processed foods.

Development of Enriched Oil with Polyphenols Extracted from Olive Mill Wastewater.

The extraction of olive oil produces significant residual olive-mill wastewater (OMW). The composition of OMW varies according to the type of olive, the fruit's ripeness level, and the extraction method (traditional one-pressing system or continuous systems based on centrifugation of the olive pulp). In olive-producing countries, OMW is important for the environment and the economy and is also a low-cost source of polyphenolic compounds with high antioxidant properties. Olive oil's properties, such as its anti-atherogenic, anti-inflammatory, anti-aging, and immunological modulator effects, have been attributed to its polyphenols. In this study, the cloud point extraction (CPE) method was used to recover polyphenolic compounds from OMW. The total micellar phase of the three recoveries was 24.2% and the total polyphenols (after sonication) was 504 mg GAE/Kg. Furthermore, the addition of polyphenols recovered from OMW enhanced the olive oil and extended its shelf life without changing its organoleptic properties. There was a 42.2% change in polyphenols after 0.5% enrichment of micellar dispersions. Thus, it is suggested that the CPE method could lead to better waste management in the olive oil industry and improve the nutritional quality of food products.

Sensitive Cloud Point Extraction Method for the Determination of Isoxsuprine Hydrochloride in Pharmaceutical forms using Spectrophotometry

A simple and highly sensitive cloud point extraction process was suggested for preconcentration of micrograms amount of isoxsuprine hydrochloride (ISX) in pure and pharmaceutical samples. After diazotization coupling of ISX with diazotized sulfadimidine in alkaline medium, the azo-dye product quantitatively extracted into the Triton X-114 rich phase, dissolved in ethanol and determined spectrophotometrically at 490 nm. The suggested reaction was studied with and without extraction and simple comparison between the batch and CPE methods was achieved. Analytical variables including concentrations of reagent, Triton X-114 and base, incubated temperature, and time were carefully studied. Under the selected optimum conditions, the linearity ranges of calibration curves were 1-9 and 0.5-8 µg/mL with detection limits of 0.26 and 0.09 µg/mL of ISX for batch and CPE methods respectively. A relative standard deviation (RSD %) best than 1.98 and 2.67 % with the percentage recoveries range 100.14 and 99.63 % were obtained for both methods respectively. The proposed methods were successfully used in routine analysis of ISX in pharmaceutical forms with high accuracy and reproducibility.