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 ◽  
...  

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.

2018 ◽  
Vol 43 (1SI) ◽  
pp. 11
Author(s):  
Alessandra Aparecida Zinato Rodrigues ◽  
Antônio Augusto Neves ◽  
Maria Eliana Lopes Ribeiro De Queiroz ◽  
André Fernando De Oliveira ◽  
Lucas Henrique Figueiredo Prates ◽  
...  

The salting-out assisted liquid-liquid extraction (SALLE) was developed for the analysis of four pesticides (cypermethrin, chlorpyrifos, deltamethrin, and thiamethoxam) in water samples. For its optimization, a 2³ factorial design was used to evaluate the simultaneous behavior of three factors: sample and extraction solvent ratio, saline concentration, and stirring mode. A 1.0 mL saline solution (NaCl) was added to the single-phase mixture of water and extraction solvent to separate the phases. The mixture was stirred, allowed to stand and the top organic phase containing the pesticides of interest was analyzed by gas chromatography coupled with electron capture detector (GC/ECD). The optimized method was validated for some merit figures. The limit of detection of the method ranged from 0.15 to 5.5 µg L-1 and the limit of quantification from 5.5 to 18.2 µg L-1. The method showed satisfactory results for the linearity (R2 ≥ 0,990), precision (CV < 9 %) and accuracy (72 % ≤ recovery ≤ 90 %) for all the assessed analytes. The method showed to be simple, efficient and inexpensive for the extraction of pesticide residues. The validated method was applied to ten samples of water collected in the Zona da Mata region of the state of Minas Gerais, Brazil.


2015 ◽  
Vol 93 (11) ◽  
pp. 1283-1289 ◽  
Author(s):  
J. Luong ◽  
R. Gras ◽  
K. Gras ◽  
R.A. Shellie

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.


Author(s):  
Rebecca A Mastrovito ◽  
Donna M Papsun ◽  
Barry K Logan

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 &gt;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.


2009 ◽  
Vol 6 (4) ◽  
pp. 1077-1084 ◽  
Author(s):  
Mohammad Reza Jamali ◽  
Yaghoub Assadi ◽  
Reyhaneh Rahnama Kozani ◽  
Farzaneh Shemirani

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.


1994 ◽  
Vol 77 (6) ◽  
pp. 1627-1630 ◽  
Author(s):  
Ana M Martín ◽  
Mercedes Sánchez ◽  
Pedro Espinosa ◽  
Gracia Bagur

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.


Author(s):  
RIMADANI PRATIWI ◽  
RASPATI D. MULYANINGSIH ◽  
NYI M. SAPTARINI

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.


2009 ◽  
Vol 92 (3) ◽  
pp. 757-764 ◽  
Author(s):  
Ellen Figueiredo Freire ◽  
Keyller Bastos Borges ◽  
Hélio Tanimoto ◽  
Raquel Tassara Nogueira ◽  
Lucimara Cristiane Toso Bertolini ◽  
...  

Abstract A simple method was optimized and validated for determination of ractopamine hydrochloride (RAC) in raw material and feed additives by HPLC for use in quality control in veterinary industries. The best-optimized conditions were a C8 column (250 4.6 mm id, 5.0 m particle size) at room temperature with acetonitrile100 mM sodium acetate buffer (pH 5.0; 75 + 25, v/v) mobile phase at a flow rate of 1.0 mL/min and UV detection at 275 nm. With these conditions, the retention time of RAC was around 5.2 min, and standard curves were linear in the concentration range of 160240 g/mL (correlation coefficient 0.999). Validation parameters, such as selectivity, linearity, limit of detection (ranged from 1.60 to 2.05 g/mL), limit of quantification (ranged from 4.26 to 6.84 g/mL), precision (relative standard deviation 1.87), accuracy (ranged from 96.97 to 100.54), and robustness, gave results within acceptable ranges. Therefore, the developed method can be successfully applied for the routine quality control analysis of raw material and feed additives.


2019 ◽  
Vol 9 (20) ◽  
pp. 4321
Author(s):  
Sas ◽  
Domínguez ◽  
González

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.


Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3422
Author(s):  
Shuyu Zhan ◽  
Amy Paik ◽  
Felicia Onyeabor ◽  
Baoyue Ding ◽  
Sunil Prabhu ◽  
...  

Celastrol (CL), a compound isolated from Tripterygium wilfordii, possesses various bioactivities such as antitumor, anti-inflammatory and anti-obesity effects. In previous studies, we developed CL-encapsulated silk fibroin nanoparticles (CL-SFNP) with satisfactory formulation properties and in vitro cancer cytotoxicity effect. For further in vivo oral bioavailability evaluation, in this study, a simple and reliable LC-MS/MS method was optimized and validated to determine CL concentration in rat plasma. The separation of CL was performed on a C18 column (150 by 2 mm, 5 µm) following sample preparation using liquid–liquid extraction with the optimized extraction solvent of tert-butyl methylether. The assay exhibited a good linearity in the concentration range of 0.5–500 ng/mL with the lower limit of quantification (LLOQ) of 0.5 ng/mL. The method was validated to meet the requirements for bioassay with accuracy of 91.1–110.0%, precision (RSD%) less than 9.1%, extraction recovery of 63.5–74.7% and matrix effect of 87.3–101.2%. The developed method was successfully applied to the oral bioavailability evaluation of CL-SFNP. The pharmacokinetic results indicated the AUC0-∞ values of CL were both significantly (p < 0.05) higher than those for pure CL after intravenous (IV) or oral (PO) administration of equivalent CL in rats. The oral absolute bioavailability (F, %) of CL significantly (p < 0.05) increased from 3.14% for pure CL to 7.56% for CL-SFNP after dosage normalization. This study provides valuable information for future CL product development.


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