Liquid Liquid Extraction Research Papers (original) (raw)

Ethyl glucuronide (EtG) is a minor and direct metabolite of ethanol. EtG is incorporated into the growing hair allowing retrospective investigation of chronic alcohol abuse. In this study, we report the development and the validation of a... more

Ethyl glucuronide (EtG) is a minor and direct metabolite of ethanol. EtG is incorporated into the growing hair allowing retrospective investigation of chronic alcohol abuse. In this study, we report the development and the validation of a method using gas chromatography–negative chemical ionization tandem mass spectrometry (GC–NCI-MS/MS) for the quantification of EtG in hair. EtG was extracted from about 30mg

Polycyclic aromatic hydrocarbons (PAHs) are environmental carcinogenic compounds that may contaminate vegetable oils and their levels can be reduced by refining. In order to understand the influence of the refining steps, the content of... more

Polycyclic aromatic hydrocarbons (PAHs) are environmental carcinogenic compounds that may contaminate vegetable oils and their levels can be reduced by refining. In order to understand the influence of the refining steps, the content of 15 PAHs was assessed throughout alkaline refining in soybean, sunflower and olive oil samples. Eight commercial brands of these oils were also analysed. The analytical method involved a liquid–liquid extraction, a solid-phase clean up (C18 and Florisil) followed by RP-HPLC with fluorimetric detection. The total PAHs content in the studied samples can be considered generally low. The light PAHs (2–4 rings) were predominant. Virgin olive oils showed the highest values (max. 26 μg/kg). An evident decrease of PAHs contents during alkaline refining was observed (71%, 88% and 85% in sunflower, soybean and olive oils, respectively) being more pronounced in light PAHs. Neutralization and, particularly, deodorization were the more effective steps contributing...

An RP-LC method was developed and validated for comparing the pharmacokinetics profile of Vasa Swaras (leaf juice of Adhatoda vasica Nees., Fam. Acanthaceae) with that of the pure vasicine and vasicinone (chief marker compounds of A.... more

An RP-LC method was developed and validated for comparing the pharmacokinetics profile of Vasa Swaras (leaf juice of Adhatoda vasica Nees., Fam. Acanthaceae) with that of the pure vasicine and vasicinone (chief marker compounds of A. vasica) upon oral administration of Vasa Swaras in rats, and also in different animal groups. Significant difference with p < 0.05 was found in the oral bioavailability of vasicine and vasicinone when administered as Vasa Swaras and as single vasicine and/or vasicinone. Vasicine and vasicinone were found to be more bioavailable from Vasa Swaras than pure vasicine and/or vasicinone.

The extraction behaviour of Ni(II), Zn(II), Cd(II), Hg(II) and Pb(II) from aqueous solution, as function of pH, has been investigated with chloroform solutions of 1-phenyl-3-hydroxy-4-dodecyldithiocarboxylate-5-pyrazolone (HDTC-12) as... more

The extraction behaviour of Ni(II), Zn(II), Cd(II), Hg(II) and Pb(II) from aqueous solution, as function of pH, has been investigated with chloroform solutions of 1-phenyl-3-hydroxy-4-dodecyldithiocarboxylate-5-pyrazolone (HDTC-12) as extractant. In each case, the extracted species was found to be M(DTC-12)2 and the extraction constants were deduced by non-linear regression analysis. The results demonstrate that this ligand extracts selectively Hg(II) from Cd(II) as well as from Pb(II).

Xylitol was produced by Candida guilliermondii by fermentation of sugarcane bagasse hemicellulosic hydrolysate. Undesirable impurities were extracted from the broth using either ethyl acetate, chloroform or dichloromethane. The best... more

Xylitol was produced by Candida guilliermondii by fermentation of sugarcane bagasse hemicellulosic hydrolysate. Undesirable impurities were extracted from the broth using either ethyl acetate, chloroform or dichloromethane. The best results on clarification of the broth without xylitol loss were obtained with ethyl acetate. When ethanol, acetone or tetrahydrofuran were used for precipitation of impurities, only tetrahydrofuran clarified the fermented broth, but a high xylitol loss (~30%) was observed.

The separation of lactic acid from complex fermentation broth was examined. Liquid-liquid extraction using reversible chemical complexation for reactive extraction was chosen to be the separation method. Over 50% yield of lactic acid was... more

The separation of lactic acid from complex fermentation broth was examined. Liquid-liquid extraction using reversible chemical complexation for reactive extraction was chosen to be the separation method. Over 50% yield of lactic acid was obtained from fermented broth in a single extraction step, when using the tertiary amine as the extractant, 1-dekanol as the diluent and trimethylamine (TMA) as the stripping solution. The effect of complex media on the extraction behaviour has hardly been examined previously.

Paraphenylenediamine is an aromatic amine used as a hair dye; it is responsible for poisoning characterized by respiratory distress involving life-threatening. The objective of this work is the development and validation of an assay of... more

Paraphenylenediamine is an aromatic amine used as a hair dye; it is responsible for poisoning characterized by respiratory distress involving life-threatening. The objective of this work is the development and validation of an assay of para-phenylenediamine in the whole blood. The method is based on the determination of paraphenylene diamine in whole blood by gas chromatography-mass spectrometry after liquid-liquid extraction and derivatization. The validation protocol has included the study of the recovery factor of extraction, the measurement range, accurency, repetability and intermediate precision. The calibration curve was linear between 98 and 1350 μg/L (r = 0.999), the limit of detection and quantification were 37 μg/L and 63 μg/L respectively. The accuracy were 94.7%. Coefficients of variation were (2.3/6.8/9.7%) for repeatability and (4.4/8.7/9.8%) for intermediate precision. The method is suitable for quantification of PPD in acute poisoning situations. A method for the de...

The aim of this work is to investigate extraction of ruthenium(III) from acidic aqueous solutions with such phosphonium ionic liquids as: trihexyl(tetradecyl)phosphonium chloride (Cyphos IL 101), trihexyl(tetradecyl)phosphonium... more

The aim of this work is to investigate extraction of ruthenium(III) from acidic aqueous solutions with such phosphonium ionic liquids as: trihexyl(tetradecyl)phosphonium chloride (Cyphos IL 101), trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate (Cyphos IL 104) and tributyl(tetradecyl)phosphonium chloride (Cyphos IL 167) as extractants. The influence of HCl content in the feed solutions on extraction of Ru(III) was investigated. The research was performed for model solutions containing Ru(III) and a mixture of waste solutions containing Ru(III) and Rh(III). Also, investigation of the type of extractant and its concentration in the organic phase on extraction of Ru(III) was carried out. Co-extraction of protons to the organic phase was determined. To the best of our knowledge, the extraction of Ru(III) with Cyphos IL 167 (tributyl(tetradecyl)phosphonium chloride) as an extractant has not yet been described in the scientific literature.

Biodiesel production from abundant bio-sources has drawn the attention of the academic as well as the industrial communities in recent years. However, one of the most serious obstacles for using biodiesel as an alternative fuel is the... more

Biodiesel production from abundant bio-sources has drawn the attention of the academic as well as the industrial communities in recent years. However, one of the most serious obstacles for using biodiesel as an alternative fuel is the complicated and costly purification processes involved in its production. The difficulties involved in the separation of glycerine and other un-reacted reactants and by-products necessitate the development of new competent low cost separation processes for this purpose. In this work, a low cost quaternary ammonium salt–glycerine-based ionic liquid is proposed as a solvent for extracting glycerine from the transesterification biodiesel product. The separation technique was tested on palm oil-based produced biodiesel with KOH as a reaction catalyst. The study investigated the effect of DES:biodiesel ratio and the DES composition on the efficiency of the extraction process. The lab scale purification experiments proved the viability of the separation technique with a best DES:biodiesel molar ratio of 1:1 and a DES molar composition of 1:1 (salt:glycerine). The purified biodiesel fulfilled the EN 14214 and ASTM D 6751 standard specifications for biodiesel fuel in terms of glycerine content. A continuous separation process is suggested for industrial scale application.

Recovering lipids from potsherds has always been important to archaeologists because of the data that can be recovered . With the advance of science, even lipid extraction is starting to improve by finding new methods that need fewer... more

Recovering lipids from potsherds has always been important to archaeologists because of the data that can be recovered . With the advance of science, even lipid extraction is starting to improve by finding new methods that need fewer samples and less time to collect results. In 2000 York University developed a more efficient method to extract lipids from archaeological potsherds with sulfuric acid. This project compared this new technique with conventional solvent extraction by BSTFA and saponification methods to test which technique is the more appropriate to recover residues from ceramic walls. The solvent extraction proved to be the procedure that recovers every main molecule of the compounds tested, while the saponification and sulphuric acid techniques derivatized the molecules. The sulfuric acid method was long to conduct, increasing the chances to contaminate the samples. This novel method proved to yield higher recoveries of lipids, but at the same time there has been compositional information loss due to hydrolysis of lipids, in fact no wax esters or TAG molecules were recovered. The only molecule that this method was not able to derivatize is cholesterol from the pistacia spp resin. It is recommended to proceed with this method if the conditions of the sample are in a poor conservation state, to make sure that more lipids are recovered from the ceramic walls. It is also useful to further analyse molecules obtained with other extraction methods to conduct more studies on them.

A multi-residue method using liquid–liquid extraction (LLE) followed by centrifugation, freezing and dispersive solid phase extraction (dispersive SPE) as clean up steps and gas chromatography with mass spectrometric detection has been... more

A multi-residue method using liquid–liquid extraction (LLE) followed by centrifugation, freezing and dispersive solid phase extraction (dispersive SPE) as clean up steps and gas chromatography with mass spectrometric detection has been developed for the ...