Oligoethylene Glycol Monoalkyl Ether Research Articles

Cloud point extraction-flame atomic absorption spectrometry method for preconcentration and determination of trace cadmium in water samples.

A method based on cloud point extraction (CPE) separation/preconcentration of trace cadmium (Cd) as a prior step to its determination by flame atomic absorption spectrometry has been developed. Cadmium reacted with 8-hydroxyquinoline to form hydrophobic chelates, which were extracted into the micelles of nonionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) in an alkaline medium. Octanol was used to depress the cloud point of Genapol X-080 in the extraction process. The chemical variables that affect the CPE, such as pH of complexation reaction, amount of chelating agent, Genapol X-080 and octanol were evaluated and optimized. Under optimized conditions, linearity was obeyed in the range of 10-500 μg/L, with the correlation coefficient of 0.9993. For 5 mL of sample solution, the enhancement factor was about 20. The limit of detection and limit of quantification of the method were 0.21 and 0.63 μg/L, respectively. The relative standard deviations (n = 6) was 3.2% for a solution containing 100 μg/L of Cd. The accuracy of the preconcentration system was evaluated by recovery measurements on spiked water samples. Recoveries of spiked samples varied in the range of 94.1-103.8%.

Micelle-Mediated Extraction of Dibenzocyclooctadiene Lignans from Schisandra chinensis with Analysis by High-Performance Liquid Chromatography

Micelle-mediated extraction offers a convenient alternative to conventional extraction systems. A new method based on micelle-mediated extraction was developed for the separation and determination of dibenzocyclooctadiene lignans from Schisandra chinensis by high-performance liquid chromatography with photodiode array detection. Various experimental conditions using the micelle-mediated method were investigated to evaluate the extraction process. Ethylene glycol monoalkyl ether (Genapol X-080), a non-ionic surfactant oligoethylene glycol monoalkyl ether, was chosen as the extract solvent. The chromatographic separation was accomplished on a Shiseido Capcell Pak C18 analytical column (250 × 4.6mm i.d., 5 µm particle diameter), detected by ultraviolet absorption at 254 nm. The isocratic elution was achieved with a mobile phase composed of water-acetonitrile-formic acid (70:30:0.1) at a flow rate of 0.6 mL/min. The method was optimized and fully validated against dibenzocyclooctadiene lignans (schizandrin, gomisin A and gomisin N). With 15% Genapol X-080, a liquid to solid ratio of 100:1 (mL/g) and ultrasonic-assisted extraction for 60 min, the extraction percentage of total dibenzocyclooctadiene lignans reached the highest value. The non-ionic surfactant Genapol X-080 solution is an effective alternative for the extraction of bioactive lignans from S. chinensis.

Ultrasonic-assisted Micellar Extraction and Cloud-point Pre-concentration of Major Saikosaponins in Radix Bupleuri using High Performance Liquid Chromatography with Evaporative Light Scattering Detection

A new ultrasonic-assisted micellar extraction and cloud-point pre-concentration method was developed for the determination of major saikosaponins, namely saikosaponins -A, -C and -D, in Radix Bupleuri by high performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD). The non-ionic surfactant Genapol X-080 (oligoethylene glycol monoalkyl ether) was chosen as the extraction additive and parameters affecting the extraction efficiency were optimized. The highest yield was obtained with 10% (w/v) Genapol X-080, a liquid/solid ratio of 200:1 (mL/g) and ultrasonic-assisted extraction for 40 min. In addition, the optimum cloud-point pre-concentration was reached with 10% sodium sulfate and equilibration at for 30 min. Separation was achieved on an Ascentis Express C18 column (100 4.6 mm i.d., 2.7 ) using a binary mobile phase composed of 0.1% acetic acid and acetonitrile. Saikosaponins were detected by ELSD, which was operated at a drift tube temperature and 3.0 bar nebulizer gas () pressure. The water-based solvent modified with Genapol X-080 showed better extraction efficiency compared to that of the conventional solvent methanol. Recovery of saikosaponins ranged from 93.1 to 101.9%. An environmentally-friendly extraction method was successfully applied to extract and enrich major saikosaponins in Radix Bupleuri.

Removal of Polyphenols from Wine Sludge Using Cloud Point Extraction

Cloud point extraction (CPE), a promising and simple technique for the separation of organic compounds using surfactants (Genapol X-080 [oligoethylene glycol mono-alkyl ether] and PEG 8000 [polyethylene glycol with molecular weight of 8000]), was used to recover polyphenols from wine sludge (wine production waste). The effect of various parameters such as surfactant concentration, temperature, and pH on the percentage of phenol recovery and phase volume ratio during phenol separation from wine sludge was investigated, and the derived optimum parameters were used as the basis for the selection of CPE conditions. When a two-step CPE with a total of 4% v/v of Genapol X-080 (pH = 3.5, temperature = 55 °C, and time = 30 min) or 10% v/v of PEG 8000 (pH = 2.5, temperature = 55 °C, and time = 30 min) was applied the phenol recovery values achieved were 75.8 or 98.5%, respectively. Phenols recovered from wine sludge using the above surfactants maintained high antiradical activity as determined by the 1, 1-diphenyl-2-picrylhydrazyl method.

Application of non-ionic surfactant in the microwave-assisted extraction of alkaloids from Rhizoma Coptidis

The feasibility of employing non-ionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) as an alternative and effective solvent for the microwave-assisted extraction of alkaloids from Rhizoma Coptidis was demonstrated. When compared with commonly used solvents, 5% Genapol X-080 enhanced the extraction efficiency. Under optimal conditions, i.e. 5% acidified Genapol X-080 (v/v), microwave-assisted extraction for 10min at 100°C, the extraction recovery of alkaloids reached 92.8% in a one-step extraction. The efficiency of cloud-point preconcentration of three alkaloids was in the range 93.6–94.7% with relative standard deviation lower than 3.3% by the proposed procedure. Furthermore, the combination of microwave-assisted extraction and cloud-point extraction was shown to be a green, rapid and effective approach for alkaloids preconcentration of Rhizoma Coptidis samples.

Micelle-mediated extraction and cloud point preconcentration for the analysis of aesculin and aesculetin in Cortex fraxini by HPLC

In this paper, a micelle-mediated extraction and cloud point preconcentration method was developed for the determination of less hydrophobic compounds aesculin and aesculetin in Cortex fraxini by HPLC. Non-ionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) was employed as the extraction solvent. Various experimental conditions were investigated to optimize the extraction process. Under optimum conditions, i.e. 5% Genapol X-080 (w/v), pH 1.0, liquid/solid ratio of 400:1 (ml/g), ultrasonic-assisted extraction for 30 min, the extraction yield reached the highest value. For the preconcentration of aesculin and aesculetin by cloud point extraction (CPE), the solution was incubated in a thermostatic water bath at 55 °C for 30 min, and 20% NaCl (w/v) was added to the solution to facilitate the phase separation and increase the preconcentration factor during the CPE process. Compared with methanol, which was used in Chinese Pharmacopoeia (2005 edition) for the extraction of C. fraxini, the extraction efficiency of 5% Genapol X-080 reached higher value.

Micellar Extraction and Preconcentration of Anthraquinone Derivatives from Rhubarb Prior to Their HPLC‐DAD Determination

In this paper, the nonionic surfactant, oligoethylene glycol monoalkyl ether (Genapol X‐080), was employed for the micellar extraction and preconcentration of the five anthraquinone derivatives from rhubarb prior to HPLC analysis. Various experimental conditions were investigated to optimize the extraction process. Under optimum conditions, i.e., 10% Genapol X‐080 (w/v), liquid/solid ratio of 50:1 (mL · g−1), ultrasonic assisted extraction for 45 min, the extraction yield of anthraquinone derivatives reached the highest value. For the preconcentration of anthraquinone derivatives by cloud point extraction (CPE), the solution was incubated in a thermostatic water bath at 55°C for 45 min, and 0.24 g · mL−1 sodium sulfate was added to the solution to facilitate the phase separation and increase the preconcentration factor during the CPE process. Compared with commonly used organic solvents, 10% Genapol X‐080 has the highest extraction yield of anthraquinone derivatives. The micellar extraction and preconcentration method established in this paper is demonstrated to be a simple and effective environment friendly alternative to conventional organic solvent extraction methods.

An Approach to the Application of Microwave-Assisted Micellar Extraction and Liquid Chromatography with Ultraviolet Detection to the Extraction and Determination of Organophosphorus Pesticides in Tomato Samples

Microwave-assisted micellar extraction methodology was applied to extract a mixture of 8 organophosphorus pesticides from the cuticle of tomato samples prior to analysis by liquid chromatography with ultraviolet detection. This technique provided very good results and was simple, fast, and environmentally friendly. The pesticides under study were extracted using the nonionic surfactants polyoxyethylene 10 lauryl ether (POLE) and oligoethylene glycol monoalkyl ether (Genapol X-080). The optimal extraction variables to be applied were determined for each surfactant and then compared. POLE proved to be the most suitable for the extraction, with recoveries over 70% in the majority and relative standard deviation values under 4.8%. After validation using a tomato sample enriched with a certified mixture, the proposed method was applied to the analysis of organophosphorus pesticides in lettuce and pepper samples.

Combination of microwave assisted micellar extraction and liquid chromatography for the determination of organophosphorous pesticides in soil samples

A new methodology based on the microwave assisted micellar extraction (MAME) technique has been optimised, using soil samples, to extract and determine a mixture of the eight organophosphorous pesticides mainly used in agriculture. The pesticides under study have been extracted using the non-ionic surfactants polyoxyethylene 10 lauryl ether (POLE) and oligoethylene glycol monoalkyl ether (Genapol X-080). The optimal extraction variables, such as surfactant concentration, pH, radiation time and microwave power were determined for each surfactant. The results show the advantage of using POLE instead of Genapol X-080 for the extraction of the organophosphorus pesticides with recoveries higher than 70% for most of the compounds and relative standard deviations (RSD) below 2.6%. This method was successfully applied to fresh samples as well as to aged samples for the analysis of soils with different characteristics and compared with the traditional Soxhlet technique.

Extraction of PCDDs from Marine Sediments Using Polyoxyethylene 10 Lauryl Ether and Oligoethylene Glycol Monoalkyl Ether Surfactants

In this study, the microwave assisted micellar extraction (MAME) methodology has been optimised to extract and determine a mixture of nine polychlorinated dibenzo‐p‐dioxins (PCDD) from marine sediments. This is a very efficient extraction procedure which considerably reduces the volume of extractant to be used and the analysis time. The PCDDs under study have been extracted using the non‐ionic surfactants polyoxyethylene 10 lauryl ether (POLE) and oligoethylene glycol monoalkyl ether (Genapol X‐080), which are biodegradable, meaning that the toxical effects of the method have been avoided. The optimal extraction variables, such as surfactant and salt concentration, together with the radiation time and microwave power, were determined for each surfactant and then compared. To get the benefit of the properties that non‐ionic surfactants possess, in order to obtain a better signal of the analytes under study, the Genapol X‐080 extracts were then preconcentrated using the cloud‐point methodology, and analysed by liquid chromatography with UV detection system under the optimised conditions. The proposed method was applied to marine sediment samples from Gran Canaria and Fuerteventura islands (Canary Islands, Spain). The results were then compared with those obtained using the traditional Soxhlet extraction methodology.

Micellar extraction of organophosphorus pesticides and their determination by liquid chromatography

Methodology to extract and determine eight organophosphorus pesticides (Chlorpyrifos, Diazinon, Dimethoate, Ethoprophos, Malathion, Methidathion, Parathion methyl and Paration ethyl), that are in current use in agriculture and animal husbandry, was optimised. The surfactants used as extractants, polyoxyethylene 10 lauryl ether (POLE) and oligoethylene glycol monoalkyl ether (Genapol X-080), belong to the non-ionic surfactants family, which allow the extraction and preconcentration of the analytes under study in a single step. This procedure, known as cloud-point extraction, offers a series of advantages over the traditional methodologies applied to the extraction of organic compounds such as pesticides. The parameters and variables that affect the extraction of these substances using both surfactants were established followed by liquid chromatographic determination. The optimised method, once validated using the standard Pesticide Mix 1 (EPA Method 914), was successfully applied to spiked water samples from Gran Canaria Island.

Determination of Benzimidazole Fungicides by HPLC with Fluorescence Detection After Micellar Extraction

An analytical method was developed to determine the benzimidazole fungicides and their residues (benomyl, carbendazim, thiabendazole and fuberidazole) in real water samples. Analyses were performed by reverse phase (RP) HPLC with direct fluorescence detection with mobile phase methanol:water, 40:60 (v/v) with 0.6% (v/v) ammonia. The extraction of analytes from water samples was performed with the use of micellar systems. Specifically, oligoethylene glycol monoalkyl ether (Genapol X-080) and polyoxyethylene 10 lauryl ether (POLE) were used as extractants. The recoveries of fungicides obtained in spiked water samples ranged from 68% to 94% for Genapol and from 68% to 96% for POLE. The limit of detection (LOD) was lower than 6 μg L−1 for carbendazim, 7 μg L−1 benomyl, 0.15 μg L−1 for thiabendazole and 0.01 μg L−1 for fuberidazole in both surfactants.

Micelle-mediated extraction of tanshinones from Salvia miltiorrhiza bunge with analysis by high-performance liquid chromatography

The feasibility of employing non-ionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) as an alternative and effective solvent for the extraction of tanshinones from Salvia miltiorrhiza bunge was studied for the first time. Various experimental conditions were investigated to optimize the extraction. Under optimum conditions, i.e. 10% Genapol X-080 (w/v), liquid/solid ratio of 20:1 (ml g −1), ultrasonic-assisted extraction for 45 min, the extraction recovery of the tanshinones reached the highest value. When compared with commonly used solvents, 10% Genapol X-080 yielded almost the same extraction efficiency as methanol and dichloromethane–methanol (1:4). For the pre-concentration of tanshinones by cloud-point extraction (CPE), sodium chloride was added to the solution to facilitate the phase separation and increase the pre-concentration factor by reducing the volume of the surfactant-rich phase.

Use of non-ionic surfactant solutions for the extraction and preconcentration of phenolic compounds in water prior to their HPLC-UV detection.

A simple and rapid HPLC method with spectrophotometric detection to determine phenolic compounds in water, including the 11 priority phenolic pollutants, is described. As they are present in low concentrations, an extraction and preconcentration step is necessary prior to their determination. A methodology based on the cloud point phenomenon is applied using the non-ionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) as extractant. The optimum conditions for the extraction and preconcentration of phenolic derivatives have been established and detection limits lower than 10 micrograms L-1 were obtained for all studied compounds. The method has been applied to their determination in sea water and depurated waste water samples.

Application of microwave-assisted extraction using micellar media to the determination of polychlorinated biphenyls in marine sediments

Microwave-assisted extraction methodology has been widely used for the extraction of different compounds from soil and sediment samples. It is not a time consuming methodology (only requiring 10–30 min) and needs reduced volumes of extractant, usually organic solvents. In this work, the applicability of micellar media as extractants instead of organic solvents is examined. Micellar media have the following characteristics: low cost, reduced toxicology and easy handling. The analytes under study are polychlorinated biphenyls (PCBs), and the surfactants used are polyoxyethylene 10 lauryl ether (POLE) and oligoethylene glycol monoalkyl ether (Genapol X-080). This methodology is applied to marine sediment samples from two regions of Gran Canaria Island (Las Canteras beach in the north-east, and Taliarte harbour, south-east). The sediment samples are spiked with the analytes under study and conditioned for 24 h and 10 weeks. The results obtained show good recovery percentages for the different analytes and are compared with those obtained when Soxhlet extraction is applied to the same sediments.

Microwave-assisted extraction of organochlorine compounds in marine sediments with organized molecular systems

Analysis of marine sediments is particulary important because they are considered pollution indicators, since they present a view of the spatial distribution of pollutants. The use of microwave energy enables a simple and rapid analysis of different kinds of compounds present in these media. This work shows the results obtained during the optimization process for the application of microwave-assisted extraction methodology (MAE) to the determination of polychlorinated dibenzofurans (PCDFs), present in different marine sediment samples, as well as in mixtures with polychlorinated biphenyls (PCBs), using two non-ionic surfactants (oligoethylene glycol monoalkyl ether and polyoxyethylene 10 lauryl ether) as extractants. After extraction, the organochlorinated compounds are determined by HPLC using fluorescence detection. Recovery rates are compared with those obtained when Soxhlet extraction is used for the same purpose.

Application of cloud-point methodology to the determination of polychlorinated dibenzofurans in sea water by high-performance liquid chromatography

Polychlorinated dibenzofurans (PCDF) are organic compounds with very toxic effects for humans and the environment. As they are present in low concentrations, an extraction technique is necessary prior to their determination by high-performance liquid chromatography (HPLC). In this work, the methodology of cloud-point extraction, using two non-ionic surfactants oligoethylene glycol monoalkyl ether (Genapol X-080) and polyoxyethylene-10-cetyl ether (Brij 56), is applied to the extraction and preconcentration of PCDF in sea water samples prior to their determination by HPLC with fluorescence detection.