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Obtaining anthocyanin-rich extracts from frozen açai (Euterpe oleracea Mart.) pulp using pressurized liquid extraction

Obtaining anthocyanin-rich extracts from frozen açai (Euterpe oleracea Mart.) pulp using pressurized liquid extraction

Açai is considered a functional food, and in addition to being a source of energy and fiber, it is a valuable source of bioactive compounds such as anthocyanins, minerals and fatty acids. In the present work, antioxidant-rich extracts from açai pulp were obtained using pressurized liquid extraction (PLE). The effects of the independent variables, including solvent type (pure ethanol and ethanol/water (50:50 v/v)), citric acid (0 and 0.3%, w/w), pressure (20 and 80 bar) and temperature (30 and 60 °C) were evaluated using a full factorial design. The extraction was affected primarily by the solvent type and the citric acid percentage. The results indicate that the maximum overall yield (X 0 ) was 64 ± 9 (%, d.b.) when the process was performed using ethanol (99.5%) and citric acid (0.3% w/w). The maximum total anthocyanin content and anthocyanin recovered from the raw material were 7 ± 1 (mg anthocyanin/g extract, d.b.) and 11 ± 2 (%, d.b.), respectively.
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Avaliação de  endócrinos e do micropoluente colesterol em estações de tratamento de esgoto sanitário

Avaliação de endócrinos e do micropoluente colesterol em estações de tratamento de esgoto sanitário

natural and synthetic estrogens and their conjugates in sewage sludge by pressurized liquid extraction and liquid chromatography – tandem mass spectrometry. Investigati[r]

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Rev. bras. farmacogn.  vol.25 número2

Rev. bras. farmacogn. vol.25 número2

Some other methodologies employing pressurized liquid extraction, dispersive liquidliquid microextraction and dispersive solid phase extraction have been described in the literature for the analysis of pesticide residues in tea (Nguyen et al., 2010; Moinfar et al., 2009; Cho et al., 2008). Microwave assisted extraction (MAE) has been assayed as extraction and clean up procedure in food matrices (Vryzas et al., 2007; Papadakis et al., 2006; Vryzas et al., 2002), but there is no report for MAE in herbal teas. Its main advan- tages are low solvent consumption, short extraction time, and high level of automation with high extraction efficiency (Niell et al., 2011; Papadakis et al., 2006).
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J. Braz. Chem. Soc.  vol.24 número4

J. Braz. Chem. Soc. vol.24 número4

aromatic hydrocarbons (PAH) are carcinogenic, making their presence in foods and in the environment a health concern. Regulations around the world limit levels of a variety of PAH in drinking water, food additives, cosmetics, workplaces and factory emissions. PAH have traditionally been separated using high performance liquid chromatography with UV detection (HPLC-UV), but the limits of detection of the method of the HPLC-UV techniques, employing direct injection of samples, are too high for the detection of the low concentrations in real samples that are near the regulated limit. HPLC-fluorescence, gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID) can be use for PAH determination, but MS provides greater specificity than fluorescence (FL) or UV or FID detectors. Therefore, the analytes in these samples require preconcentration before the analysis. 6 Some petroleum derived hydrocarbons
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OPTIMIZATION OF THE EXTRACTION OF FREE FATTY ACIDS APPLIED TO BIODIESEL PRODUCTION

OPTIMIZATION OF THE EXTRACTION OF FREE FATTY ACIDS APPLIED TO BIODIESEL PRODUCTION

a higher number of stages with S/F ratios varying from 1.27 to 2. According to Mohsen-Nia and Khodayari (2008), methanol presents selectivities from 2.5 to 4 times higher than ethanol for oleic acid extraction from sunflower oil. In addition, the higher the water concentration, the more difficult the FFA separation becomes (Batista et al., 2002; Rodrigues et al., 2007). As a result, methanol presented better extraction properties than ethanol and ethanol/water mixtures requiring fewer stages and lower S/F ratios.

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O PTIMIZATION ANDV ALIDATION OF THES

O PTIMIZATION ANDV ALIDATION OF THES

The development and application of methodologies for the determination of pesticides in the soil face some obstacles, such as the concentration of these substances after application, which can be low or high, and the different types of interaction between these molecules and the soil colloids, which can form weak or strong interactions. Other factors that may alter the effectiveness of a method are connected to the properties of soils pH, texture and mineralogy, organic matter content and other components in the soil that can be coexctracted (Lourencetti et al., 2008). There are various methods of extraction and analysis for picloram herbicide in soil and water found in the literature. In general, the chromatographic techniques are the most used. (Cheng, 1969, 1971; McCaall et al., 1972; Biggar & Cheung, 1973; McKone, et al., 1974; Wells et al., 1984, 1987; Bovey & Richardson, 1991; Krzyszowska et al., 1994; Lavy et al., 1996; Bruner et al., 1996; Tan et al., 1996; Wells & Yu, 2000; Celis et al., 2002, 2005). Most of these studies were conducted in temperate soils. These soils, which somehow are relatively young and less weathered, have some characteristics different from those more weathered soils such as in Brazil’s tropical climate.
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Diazepam and nordiazepam in plasma: liquid-liquid and solid phase extraction in sample pre-treatment for high performance liquid chromatography analysis.

Diazepam and nordiazepam in plasma: liquid-liquid and solid phase extraction in sample pre-treatment for high performance liquid chromatography analysis.

DIAZEPAM AND NORDIAZEPAM IN PLASMA: LIQUID-LIQUID AND SOLID PHASE EXTRACTION IN SAMPLE PRE- TREATMENT FOR HIGH PERFORMANCE LIQUID CHROMATOGRAPHY ANALYSIS. Analysis of diazepam (DZP) and its active metabolite nordiazepam (NDZP) in plasma is commonly performed in clinical medicine to ensure proper therapeutic effects while minimizing the incidence of toxicity. This study aimed to optimize analytical parameters and compare two pre-treatment techniques, liquid-liquid (LLE) and solid phase extraction (SPE), as well as liquid chromatographic conditions to analyze simultaneously DZP and NDZP in plasma from 20 patients treated with a daily dose of 10 mg. Both techniques showed to be well in line with the international criteria for analytical validation, which permitted to quantify DZP (66.2 – 1148.6 ng mL -1 ) and NDZP
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J. Braz. Chem. Soc.  vol.18 número5

J. Braz. Chem. Soc. vol.18 número5

At the moment is indubitable the necessity to develop screening methods which can provide rapid analytical information. The conventional analytical methods usually are time-consuming because they are designed to provide detailed qualitative and quantitative information about the analytes in the sample, which normally is not mandatory for rapid decisions. In this context, the development of more rapid and efficient methodologies for the sample pretreatment is an important trend in analytical chemistry. In this context, in the present study a rapid method was developed and validated, based on liquid-liquid extraction using methanol as a solvent and on direct analyte determination in the extract by mass spectro- metry, utilizing selective ion monitoring (SIM) to determine different Aroclors (Aroclor 1242, 1254, and 1260) in transformer oil. The amount of co-extracted oil is small and it only interferes with the exact deter- mination of di-, tri-, and tretrachlorinated congeners. In this context, direct extraction with methanol followed by injection into a GC-MS permits to determine rapidly whether or not oil is contaminated above the 50 mg kg -1
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Azeotropic separation: playing with the ionicity of ionic liquids

Azeotropic separation: playing with the ionicity of ionic liquids

The work presented in this thesis explores three different combinations of ILs and ISs, namely one IL with several ISs, different ILs with one IS and one IL with different concentrations of the same IS. Studies of the impact of the addition of the IS on the IL properties, namely density, viscosity and conductivity, are presented and the ionicity of each mixture is calculated and compared with that of other IL-IS mixtures. Molecular insights on these systems are provided by the use of molecular dynamics and NMR in order to better understand the ionicity of the studied mixture. Finally, the studied IL-IS mixtures are tested in the separation of one specific azeotropic mixture, n-heptane + ethanol that will serve as test model (proof-of-concept) for the application of IL-IS mixtures as extraction solvents for breaking azeotropes. These two tasks, the IL-IS ionicity evaluation and their use in the separation of azeotropic mixtures, enable to address the underlying scientific question of this work, the existence of a link between ionicity and extraction efficiency of an azeotropic mixtures, described by the selectivity and distribution coefficient.
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ANTIMYCOBACTERIAL ACTIVITY OF A BREVIBACILLUS LATEROSPORUS STRAIN ISOLATED FROM A MOROCCAN SOIL Mohammed Hassi1 ; Souraya El Guendouzi1 ; Abdelleatif Haggoud1 ; Susana David2 ; Saad Ibnsouda1 ; Abdellah Houari1; Mohammed Iraqui1

ANTIMYCOBACTERIAL ACTIVITY OF A BREVIBACILLUS LATEROSPORUS STRAIN ISOLATED FROM A MOROCCAN SOIL Mohammed Hassi1 ; Souraya El Guendouzi1 ; Abdelleatif Haggoud1 ; Susana David2 ; Saad Ibnsouda1 ; Abdellah Houari1; Mohammed Iraqui1

The treatment of tuberculosis has become more difficult with the worldwide spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis. Moreover, the prevalence of human disease caused by atypical mycobacteria has also increased in the past two decades and has further complicated the problem of the treatment of mycobacterial infections. It is therefore urgent to develop new highly active molecules against these bacteria. The present study reports the isolation from a Moroccan soil of a Bacillus strain that exhibits an important antimycobacterial activity. The strain was identified as Brevibacillus laterosporus using DNA sequencing of the 16S ribosomal RNA gene. The antimycobacterial activity was assigned to a substance with a protein nature. This nature was revealed using a liquid-liquid extraction with organic solvents, precipitation with ammonium sulfate and treatment with a protease. This study suggested the identification and the characterization of this active metabolite enabling therapeutic investigations further.
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Recovery of metals from highly concentrated acid mine drainage by liquid-liquid extraction

Recovery of metals from highly concentrated acid mine drainage by liquid-liquid extraction

The LLE of copper from highly contaminated AMD from São Domingos mine (55.2 ± 0.3 g/L Fe; 6.2 ± 0.1 g/L Al; 4.60 ± 0.07 g/L Cu; 2.59 ± 0.03 g/L Zn and 123.9 ± 0.2 mg/L Mn) was tested using five different extractants (Acorga M5640, LIX 622, LIX 864, LIX 54 and LIX 622N) and two ionic liquids (AliCy and Cyphos 104 IL) diluted in organic solvents. Acorga M5640 was the most efficient and at 30% (v/v) dilution in Shell GTL plus 2.5 % (v/v) octanol was suitable for the complete extraction of copper from AMD, which makes an 8/1 ratio of its active compound (5-nonyl-2-hydroxy-benzaldoxime) to copper ions. The kinetics of extraction with such 30% (v/v) Acorga M5640 dilution allows total copper extraction with a contact time of 15 minutes. On another hand, a maximum loading capacity of 16 g/L Cu in the organic phase was determined by the isotherm at equilibrium and was confirmed by successive extraction cycles. Regarding the complete re-extraction of copper from the organic phase, among four stripping agents tested (H 2 SO 4 , HNO 3 , HCl and H 2 O), a
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J. Braz. Chem. Soc.  vol.22 número9

J. Braz. Chem. Soc. vol.22 número9

novel liquid-phase microextraction technique, named dispersive liquid-liquid microextraction (DLLME). This method is a miniaturized LLE that uses microliter volumes of extraction solvent and based on a ternary component solvent system in which the extraction solvent and disperser solvent are rapidly injected into the aqueous sample by syringe. The mixture is then gently shaken and a cloudy solution (water/disperser solvent/ extraction solvent) was formed in the test tube. After centrifugation, the ine particles of extraction solvent were sedimented in the bottom of the conical test tube and analyzed by analytical instruments. The advantages of DLLME method are simplicity of operation, rapidity, low cost, high-recovery, high enrichment factor, and environmental benignity, with wide application prospects in trace analysis. 5-18
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Optimization of liquid-liquid extraction step for clavulanic acid from fermentation broth using solvent mixtures.

Optimization of liquid-liquid extraction step for clavulanic acid from fermentation broth using solvent mixtures.

OPTIMIZATION OF LIQUID-LIQUID EXTRACTION STEP FOR CLAVULANIC ACID FROM FERMENTATION BROTH USING SOLVENT MIXTURES. The purpose of this work was to study four different solvent mixtures intended to increase the yield of the extraction stage of clavulanic acid (CA), which is one of the steps in the purification process. Four central composite rotatable designs (CCRD) were utilized to optimize the solvent mixtures. The variables selected for the factorial design were solvent mixture ratio (mL/mL) and temperature (ºC). The results showed that the yield of CA extracted from fermentation broth with the solvent mixtures of methyl-ethyl-ketone and ethyl acetate, and methyl-isobutyl-ketone and ethyl acetate (44.7 and 50.0%, respectively) was higher than that of the individual ethyl acetate alone (36.5%).
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Analysis of pesticides in water using liquid-liquid extraction with partition at low temperature and high performance liquid chromatography.

Analysis of pesticides in water using liquid-liquid extraction with partition at low temperature and high performance liquid chromatography.

ANALYSIS OF PESTICIDES IN WATER USING LIQUID-LIQUID EXTRACTION WITH PARTITION AT LOW TEMPERATURE AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHY. This study optimized and validated the liquid-liquid extraction technique with partition at low temperature (LLE-PLT) for identiication and quantiication of four pesticides (chlorpyrifos, λ-cyhalothrin, permethrin, bifenthrin) in water samples. Analyses were performed by HPLC-UV. The technique was eficient for pesticide recovery with extraction exceeding 86%. Chromatographic response was linear for the four compounds in the 10-45 µg L -1 range, with correlation coeficients greater than 0.99. Limits of detection and quantitation were
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LIQUID-LIQUID EQUILIBRIUM AND KINETICS OF ETHANOLIC EXTRACTION OF SOYBEAN OIL USING ETHYL ACETATE AS CO-SOLVENT

LIQUID-LIQUID EQUILIBRIUM AND KINETICS OF ETHANOLIC EXTRACTION OF SOYBEAN OIL USING ETHYL ACETATE AS CO-SOLVENT

Several alternative solvents have been proposed in substitution to hexane in oil-seed extractions, such as trichloroethylene, n-heptane, ethanol, isopropanol and propanol (Gandhi et al., 2003; Seth et al., 2007; Thomas, 2003), besides the use of other techniques such as supercritical fluid extraction (de Melo et al., 2014; dos Santos Freitas et al., 2008; Eggers et al., 1985; Koubaa et al., 2016; Rai et al., 2016; Stahl et al., 1980), compressed fluid extraction (Coelho et al., 2016; dos Santos Freitas et al., 2008; Pederssetti et al., 2011), microwave and ultrasound-assisted extraction (Adam et al., 2012; Araujo et al., 2013; Cravotto et al., 2008; Hu et al., 2012; Lee et al., 2012; Uquiche et al., 2008). Among the alternative replacements for hexane, ethanol seems to be a promising solvent for Brazilian industries, since the country is a pione- er in the technological development and production of ethanol from sugarcane, making its cost relative- ly low when compared to those obtained from other sources, such as corn or sugar beet (Baümler et al., 2016; Gandhi et al., 2003; Seth et al., 2007; Toda et al., 2016). In addition, ethanol presents lower health risks and flammability than hexane and its isomers. However, the oil solubilization in ethanol is lower (partial) than in hexane (completely miscible), what causes a reduction in extraction efficiency (Baümler et al., 2016; Gandhi et al., 2003; Seth et al., 2007).
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J. Braz. Chem. Soc.  vol.8 número6

J. Braz. Chem. Soc. vol.8 número6

The present paper describes the use of 1-(2-thiazolylazo)-p-cresol (TAC) for separation, preconcentration and determination of iron traces (ng g -1 ) in alkaline salts by the ICP-AES technique. The proposed method is based on the liquid-liquid extraction of the complex formed between iron(III) and 1-(2-thiazolylazo)-p-cresol (TAC). Parameters such as: TAC amount, pH effect, influence of the organic solvent on the extraction, back extraction and mineralization of the organic phase were studied. The results show that the iron(III)-TAC complex, formed in the pH range from 4.0 to 10.0, can be quantitatively extracted from saline solutions (up to 30% NaCl) using isoamyl alcohol, carbon tetrachloride, chloroform or methyl isobutyl ketone as extracting solvent. The solution for the iron determination can be obtained by a back extraction using 1 mol/L hydrochloric acid or 1 mol/L nitric acid solutions or also by mineralization of the organic phase, which was accomplished by evaporation of the organic solvent and digestion of the residue with concentrated nitric acid. The procedure was used for iron determination in several alkaline salt samples. The standard addition technique was applied and the recoveries obtained revealed that the proposed procedure has a good accuracy.
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Evaluation of the Extraction Process of the Essential Oil from Cymbopogon schoenanthus with Pressurized Carbon Dioxide

Evaluation of the Extraction Process of the Essential Oil from Cymbopogon schoenanthus with Pressurized Carbon Dioxide

such curves are characterized by the formation of three different areas: (i) the stage of constant extraction, where the solute is extracted essentially by convection; (ii) period of decrease rate, where convection and diffusion act; (iii) diffusional period, where the diffusion of the oil and of the mixture solute/solvent prevails in the solid. The process time of total extraction was 250 minutes, on average, during which 79.8% of the oil was extracted.

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J. Braz. Chem. Soc.  vol.17 número5

J. Braz. Chem. Soc. vol.17 número5

Whereas membrane technologies are one of the most important topics in today´s research and practical use, liquid membrane processes have been proposed as clean ones owing to their characteristics of high specificity, low energy utilisation, the extraction and stripping steps are combined in a single operation etc.; thus, the use of liquid membranes has gained a general interest in the treatment of effluents were solute concentrations are low and large volume of solutions must be processed, and if possible, without generating any secondary waste.

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J. Braz. Chem. Soc.  vol.25 número4

J. Braz. Chem. Soc. vol.25 número4

A miniaturized liquid-phase extraction procedure based on directly suspended droplet microextraction combined with flame atomic absorption spectrometry was developed for determination of trace amounts of iron and copper, without any need for the centrifugation step for phase separation. The method was based on the extraction of the iron and copper complexes with 2-mercaptopyridine-N-oxide onto a microdrop of methyl isobutyl ketone (MIBK) as extractant solvent. The factors influencing the extraction were optimized. Under optimum conditions, an enrichment factor of ~25 was obtained for both iron and copper from only 6.5 mL of aqueous phase. The analytical curves were linear between 40-800 µg L -1 and 25-1200 µg L -1 for iron and
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Liquid-liquid equilibrium for water furfural extraction using different solvents and temperatures in the software aspen plus / Equilíbrio líquido-líquido para extração de furfural da água usando diferentes solventes e temperaturas no software aspen plus

Liquid-liquid equilibrium for water furfural extraction using different solvents and temperatures in the software aspen plus / Equilíbrio líquido-líquido para extração de furfural da água usando diferentes solventes e temperaturas no software aspen plus

Braz. J. of Develop., Curitiba, v. 6, n.6, p.36035-36045 jun. 2020. ISSN 2525-8761 The extraction efficiency was compared and the data shown in Table 2. It appears that it is not prudent to compare the values of D and S obtained from the molar fractions obtained experimentally and in modeling, since among solvents there is a significant discrepancy. However, an observation can be made from the perspective of the best removal process. Thus, the scale of better solvent extraction capacity can be obtained. The highest levels of efficiency and extraction factor obtained were p-Xylene and Toluene in both situations.
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