scholarly journals Piston-cylinder based micro liquid–liquid extraction with GC–qMS for trace analysis of targeted chlorinated organic compounds in water

2015 ◽  
Vol 93 (11) ◽  
pp. 1283-1289 ◽  
Author(s):  
J. Luong ◽  
R. Gras ◽  
K. Gras ◽  
R.A. Shellie
Keyword(s):  
Detection Limit ◽  
Complete Separation ◽  
Liquid Extraction ◽  
Extraction Technique ◽  
Chlorinated Organic Compounds ◽  
Mechanical Agitation ◽  
Extraction Solvent ◽  
Piston Cylinder ◽  
Liquid Liquid Extraction ◽  
Relative Standard

A fast and reliable approach for the measurement of sub parts-per-billion levels of targeted chlorinated compounds like tetrachloroethane, hexachloroethane, hexachlorobutadiene, pentachlorobenzene, and hexachlorobenzene in various water matrices such as waste water is described. The method employed a novel piston-cylinder-based micro liquid–liquid extraction technique using hexane as an extraction solvent. The device, known commercially as the MIXXOR, substantially accelerates extraction time by a factor of more than 100 times and reduces solvent consumption by a factor of 25 times when compared with the solvent extraction technique using wrist-action mechanical agitation. A recently introduced 6% cyanopropylphenyl –94% dimethylpolysiloxane capillary column offering a high degree of inertness was used for the separation of the analytes. A quadrupole mass spectrometer equipped with a triple-axis detector was also employed to enhance the instrument detection limit. With this technique, a complete separation for the analytes in water can be conducted in less than 10 min using a three-port SilFlow planar microfluidic device for back-flushing. Repeatability of retention times for all compounds were found to be less than 0.04% (n = 10). The compounds cited can be analyzed from 1 ng/mL to 10 μg/mL, with a detection limit and correlation coefficient of at least 0.5 ng/mL and 0.999, respectively. A relative precision of less than 1.2% relative standard deviation (RSD) (n = 20) at the 50 ng/mL level, with analyte recovery of greater than 99% (n = 3) from 10 ng/mL to 10 μg/mL, was obtained.

scholarly journals A fast, low-cost and eco-friendly method for routine determination of Bisphenol-A in landfill leachate employing vortex assisted liquid-liquid extraction

2021 ◽  
Vol 4 (03) ◽  
pp. 59-67
Author(s):  
Gustavo Fehrenbach ◽  
Daniel Ricardo Arsand ◽  
Sergiane Caldas Barbosa ◽  
Kátia Castagno ◽  
Pedro Filho ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Low Cost ◽  
Liquid Extraction ◽  
Effluent Treatment ◽  
Limit Of Quantification ◽  
Synthetic Compound ◽  
Simple Method ◽  
Extraction Solvent ◽  
Liquid Liquid Extraction ◽  
Relative Standard

Landfills are sites designed to receive and final disposal of a broad variety of urban solid wastes (USW). The decomposition and biodegradation processes generate a leachate of high complexity and toxicity, containing persistent and recalcitrant contaminants that are not usually monitored. Bisphenol-A (BPA) is a synthetic compound applied mostly on the production of polycarbonate plastics, epoxy resins, and is an endocrine disruptor. The presence of BPA in USW urges the development of feasible analytical methods to support the effluent treatment plants and reduce the risks of contamination. The main goal of this work was to develop an efficient, eco-friendly, fast and simple method for routine analysis of BPA in the leachate from landfill. A vortex assisted liquid-liquid extraction (VALLME) using 1-octanol as solvent was performed. BPA recoveries at spiking levels of 2.5, 6.5 and 12.5 µg L-1 were between 60 to 104% with relative standard deviation (RSD) lower than 26%. The linearity of the method was evaluated and the correlation coefficient was (r) 0.9985. The limit of quantification (LOQ) was 2.5 µg L-1 with a pre-concentration factor of 20. The method has advantages such as low consumption of extraction solvent (150 µL), low cost, easy and fast determination.

Determination of Bromate Ions in Drinking Water by Derivatization with 2-Methyl-2-Butene, Dispersive Liquid-Liquid Extraction and Gas Chromatography-Electron Capture Detection

2020 ◽  
Vol 103 (5) ◽  
pp. 1243-1249
Author(s):  
Mehdi Nabi ◽  
Sayed Mehdi Ghoreishi ◽  
Mohsen Behpour
Keyword(s):  
Gas Chromatography ◽  
Detection Limit ◽  
Electron Capture ◽  
Liquid Extraction ◽  
International Standards ◽  
Electron Capture Detection ◽  
Liquid Liquid Extraction ◽  
Relative Standard ◽  
Derivatizing Agent

Abstract Background A simple, rapid, selective and sensitive sample preparation and derivatization method was performed for determination of bromate ions in water by means of dispersive liquid-liquid extraction (DLLE) by gas chromatography-electron capture detection (GC-ECD). This method is based on 2-methyl-2-butene derivatization by bromine produced from bromate ions in acidic medium and extraction by n-hexane. Objective Derivatizing agent: It is cheap and available and it has high efficiency in reaction with Br2. Simplicity: Preparation and extraction process don't need to any specific equipment and procedure is completely simple and fast. Limit of detection: DL is as low as 0.43 µg/L. Methods Various effective factors on the derivatization and extraction efficiency, such as amount of derivatizing agent, volume of extraction solvent, bromide concentration, volume and concentration of sulfuric acid, type and volume of extracting and dispersing solvent, ionic strength, storage time before extraction and ECD makeup-gas flow rate were investigated. Results Under the optimum conditions, the method had a linear calibration curve ranging from 1.0 to 200.0 µg/L for bromate ions with a determination coefficient (R2) of 0.994 and the detection limit was 0.43 µg/L. The recovery percent and relative standard deviation for the determination of 1.0, 5.0 and 50.0 µg/L bromate ion was between 90 and 110%, and 3.0 and 8.0% (n = 3), respectively. Conclusions Finally, the method was successfully applied for the preconcentration and determination of bromate ions in water samples, and satisfactory results were obtained. Highlights (1) Fast, easy, accurate and economical innovative analysis of bromate ions in water and wastewater. (2) Determination of inorganic ion by GC-ECD after derivatization (3) Low detection limit (4) Optimization of different method parameters to obtain accurate results based on requirements of international standards, specifically ISO/IEC 17025.

scholarly journals The Development and Validation of a Novel Designer Benzodiazepines Panel by LC–MS-MS

2021 ◽  
Author(s):  
Rebecca A Mastrovito ◽  
Donna M Papsun ◽  
Barry K Logan
Keyword(s):  
Illicit Drug ◽  
Liquid Extraction ◽  
Electrospray Tandem Mass Spectrometry ◽  
Method Performance ◽  
Internal Standards ◽  
Liquid Liquid Extraction ◽  
Relative Standard ◽  
Development And Validation ◽  
Positive Ion ◽  
Designer Benzodiazepines

Abstract Novel illicit benzodiazepines are among the most active areas of new illicit drug manufacture and use. We describe a method for the detection and quantification of etizolam and its metabolite α-hydroxyetizolam, flubromazolam, clonazolam, diclazepam, delorazepam, bromazepam, flubromazepam, phenazepam, flualprazolam, flunitrazolam, and nitrazolam in human whole blood. After addition of internal standards, samples are buffered and extracted using a liquid–liquid extraction. Analysis is performed using positive-ion electrospray tandem mass spectrometry for detection and quantitation. Calibration ranges were established based on the method performance and differed from compound to compound. Replicates at the lowest calibration point for each compound performed within 5% of CV (Coefficient of Variation). The correlation coefficient was >0.990 for all compounds. Relative standard deviation for all compounds was ≤10% of CV and accuracy was  ±10% for both within- and between-run experiments. The maximum average intra- and inter-run imprecision were 5.7%. The maximum average intra- and inter-run imprecision was −8.7%. As part of evaluating the scope for relevancy, samples testing positive in immunoassay but confirmed to be negative in traditional benzodiazepine confirmation method were re-analyzed using this method. The presence of at least one novel benzodiazepine was identified in 70% of these samples. The appearance of these novel “designer” benzodiazepines demonstrates the challenge for toxicology testing and the need for continually updated confirmation methods.

Development of a rotatory and continuous liquid–liquid extraction technique for phenolic compounds in wine

The Analyst ◽  
1996 ◽  
Vol 121 (3) ◽  
pp. 297-302 ◽  
Author(s):  
E. R. Brú ◽  
C. G. Barroso ◽  
R. Cela ◽  
J. A. Pérez-Bustamante
Keyword(s):  
Phenolic Compounds ◽  
Liquid Extraction ◽  
Extraction Technique ◽  
Liquid Liquid Extraction

scholarly journals Homogeneous Liquid-Liquid Extraction Method for Selective Separation and Preconcentration of Trace Amounts of Palladium

2009 ◽  
Vol 6 (4) ◽  
pp. 1077-1084 ◽  
Author(s):  
Mohammad Reza Jamali ◽  
Yaghoub Assadi ◽  
Reyhaneh Rahnama Kozani ◽  
Farzaneh Shemirani
Keyword(s):  
Extraction Method ◽  
Limit Of Detection ◽  
Liquid Extraction ◽  
Selective Separation ◽  
Complexing Agent ◽  
Homogeneous Liquid ◽  
Liquid Liquid Extraction ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Ternary Component System

A simple and effective homogeneous liquid-liquid extraction method for selective separation, preconcentration and spectrophotometric determination of palladium(II) ion was developed by using a ternary component system (water / tetrabutylammonium ion (TBA+) / chloroform). The phase separation phenomenon occurred by an ion–pair formation of TBA+and perchlorate ion. Thio-Michler’s ketone (TMK), 4, 4ˊ-bis (dimethylamino) thiobenzophenone, was used as a complexing agent. After optimization of complexation and extraction conditions ([TMK]=5.0x10-2mol L-1, [TBA+] = 2.0×10-2mol L-1, [CHCl3] = 60.0 µL, [ClO4-] = 2.5×10-2mol L-1and pH= 3.0), a preconcentration factor 10 was obtained for 10 mL of sample. The analytical curve was linear in the range of 2-100 ng mL-1and the limit of detection was 0.4 ng mL-1. The relative standard deviation was 3.2% (n=10). Accuracy and application of the method was estimated by using test samples of natural and synthetic water spiked with different amounts of palladium(II) ion. The method is very simple and inexpensive.

Determination of Tin in Canned Fruits and Vegetables by Atomic Absorption Spectrometry and Liquid–Liquid Extraction

1994 ◽  
Vol 77 (6) ◽  
pp. 1627-1630 ◽  
Author(s):  
Ana M Martín ◽  
Mercedes Sánchez ◽  
Pedro Espinosa ◽  
Gracia Bagur
Keyword(s):  
Aqueous Phase ◽  
Fruits And Vegetables ◽  
Methyl Ketone ◽  
Absorption Spectrometry ◽  
Liquid Extraction ◽  
Acid Complex ◽  
Liquid Liquid Extraction ◽  
Relative Standard ◽  
Good Agreement

Abstract A method was developed for the determination of tin based on the extraction of its 5,5-methylenedisalicylohydroxamic acid complex with 1.09M isobutyl methyl ketone in tributyl phosphate. After the samples were treated with nitric and hydrochloric acid, the aqueous phase was made to 0.05M in perchloric acid. When the ratio of aqueous phase to organic phase was 4:1 (v/v), the detection limit and the relative standard deviation (n = 7,50 μg tin) were 0.20 μg/mL and 0.9%, respectively. The proposed method was applied to the analysis of tin in canned fruits and vegetables. The results were in good agreement with those obtained by the phenylfluorone method.

scholarly journals COMPARISON OF THREE EXTRACTION METHODS OF ALLOPURINOL IN URIC ACID HERBAL MEDICINE WITH HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY QUANTIFICATION

2021 ◽  
pp. 141-147
Author(s):  
RIMADANI PRATIWI ◽  
RASPATI D. MULYANINGSIH ◽  
NYI M. SAPTARINI
Keyword(s):  
Herbal Medicine ◽  
High Performance ◽  
Solid Phase ◽  
Extraction Methods ◽  
Liquid Extraction ◽  
Filtering Method ◽  
Liquid Liquid Extraction ◽  
Accuracy And Precision ◽  
Relative Standard ◽  
Parameters Of Accuracy

Objective: This study was aimed to understand and determine the effectiveness of allopurinol extraction in herbal medicine from three extraction methods based on parameters of accuracy and precision. Methods: The study consisted of three methods including dissolving and filtering, liquid-liquid extraction, and solid-phase extraction with mixed-mode cation exchanger (SPE-MCX). The procedures were carried out using NaOH and HCl in dissolving and filtering method; methanol, HCl, and ethyl acetate in liquid-liquid extraction; and NH4OH elution solvent in SPE-MCX. Results: The results showed that extraction effectiveness based on accuracy level was the dissolving and filtering method>SPE-MCX>liquid-liquid extraction with % recovery+SD of 91.314+2.903%, 87.533+4.950%, and 54.549+3.517%, respectively. The precision level was the dissolution and filtering method>SPE-MCX>liquid-liquid extraction based on % relative standard deviations (RSD) of 3.18%, 5.226%, and 6.446%, respectively. Conclusion: It can be concluded that the allopurinol extraction method with the highest effectiveness based on accuracy and precision parameters in herbal medicine is the dissolving and filtering method.

scholarly journals Recovery and Elimination of Phenolic Pollutants from Water Using [NTf2] and [Nf2]-Based Ionic Liquids

2019 ◽  
Vol 9 (20) ◽  
pp. 4321
Author(s):  
Sas ◽  
Domínguez ◽  
González
Keyword(s):  
Ionic Liquids ◽  
Phenolic Compounds ◽  
Extraction Yield ◽  
Liquid Extraction ◽  
Industrial Growth ◽  
Extraction Solvent ◽  
Phenolic Pollutants ◽  
Liquid Liquid Extraction ◽  
Volatile Organic ◽  
Extraction Solvents

At present, pollution is one of the most important problems worldwide. Industrial growth makes it necessary to develop techniques to remove pollutant substances from water, since water is an important natural source for life. One of these techniques is liquid–liquid extraction, which is used to remove phenolic compounds from wastewaters. Volatile organic compounds are used as common extraction solvents in liquid–liquid extractions; nevertheless, some of their properties, such as toxicity and volatility, make it necessary to replace them with other less toxic solvents. In this work, the capability of four ionic liquids, based on bis(trifluoromethylsulfonyl)imide [NTf2] and bis(fluorosulfonyl)imide [Nf2] anions and different cations to remove phenolic compounds from water was studied. The phenolic compounds used in this study were phenol, o-cresol, and 2-chlorophenol, and the effects of the extraction solvent and phenol structures were analyzed. For that, a liquid–liquid extraction was carried out, and the extraction yield was determined. In general, high extraction efficiencies were obtained for all studied systems, obtaining the highest extraction efficiencies using the pyrrolidinium cation-based ionic liquids.

Selection of a recyclable in situ liquid–liquid extraction solvent for foam-free synthesis of rhamnolipids in a two-phase fermentation

2020 ◽  
Vol 22 (23) ◽  
pp. 8495-8510 ◽  
Author(s):  
Philipp Demling ◽  
Maximilian von Campenhausen ◽  
Carolin Grütering ◽  
Till Tiso ◽  
Andreas Jupke ◽  
...  
Keyword(s):  
Liquid Extraction ◽  
Stirred Tank ◽  
Biotechnological Production ◽  
Two Phase ◽  
Stirred Tank Reactors ◽  
Extraction Solvent ◽  
Liquid Liquid Extraction ◽  
Extraction Solvents ◽  
Selection Of

A multi-step reductive approach for the selection of in situ extraction solvents for bioprocesses was developed enabling a foam-free biotechnological production of rhamnolipids in stirred-tank reactors.

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