Separation of the glycerol-biodiesel phases in an ethyl transesterification synthetic route using water

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Biodiesel is obtained by the transesterification of vegetable oil (or fat) and alcohol, with methanol being the most used alcohol. Methanol can be replaced by ethanol; however, this alcohol acts as a surfactant in the reaction mixture, promoting a stable dispersion of the glycerol in biodiesel, which hinders the separation of the glycerol-biodiesel phases. In this study, it was found that the addition of 1% v/v water relative to the total volume of the reaction mixture expedites the separation of the phases by interrupting the emulsifying action of ethanol with an immediate separation of glycerol from biodiesel. The characterization of the produced biodiesels was performed using hydrogen nuclear magnetic resonance (H-1 NMR) and gas chromatography (GC). H-1 NMR indicated a 96.9% conversion of triglycerides to biodiesel. The fatty acid compositions of the synthesized ethyl and methyl biodiesels determined using GC are essentially the same.Biodiesel is obtained by the transesterification of vegetable oil (or fat) and alcohol, with methanol being the most used alcohol. Methanol can be replaced by ethanolhowever, this alcohol acts as a surfactant in the reaction mixture, promoting a stabl26917451750FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)sem informaçãosem informaçãoThe authors are grateful to Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq, for financial suppor

Simple Methods via Mid-IR or H NMR Spectroscopy for the Determination of the Iodine Value of Vegetable Oils

Two methods for determining the iodine value in vegetable oils are described. One employs mid-infrared (mid-IR) spectroscopy and the other uses hydrogen nuclear magnetic resonance ( 1 H NMR). The determination of the iodine value is based on either the transmittance intensity of mid-IR signals or on the 1 H NMR signal integration and multivariate calibration. Both of the methods showed adequate coefficients of determination (r 2 = 0.9974 and 0.9978, respectively) when compared to Wijs method, which is recommended by the norm EN 14111. A statistical comparison between the results from the proposed methods and from Wijs method shows that both instrumental methods offer equivalent results and greater precisions compared to Wijs method. The regressions obtained from the constructed models were considered statistically significant and useful for making predictions. The proposed methods present several advantages compared to Wijs method because they significantly reduce analysis time, reagent consumption and waste generation. Furthermore, an analyst can choose between the mid-IR or 1 H NMR to determine the iodine value

Quantification Of Methanol In Biodiesel Through H-1 Nuclear Magnetic Resonance Spectroscopy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Two methods are proposed for the quantitative analysis of residual methanol in biodiesel. Both of them use hydrogen nuclear magnetic resonance spectroscopy (H-1 NMR) as the main analytical tool. The first one applies the standard addition method, in which methanol is added directly to aliquots of the analyzed sample, while the other one employs tert-butyl methyl ether as an internal standard. Statistical comparisons between the results obtained from the methods proposed here and from the gas chromatographic method which is recommended by the European Standard EN 14110 show that both spectroscopic methods offer equivalent results compared with the standard one. Therefore, the two spectroscopic methods developed to quantify methanol in biodiesel are proposed here as alternatives to the official method. (C) 2016 Elsevier Ltd. All rights reserved.17599104CNPqConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Alternative methods to quantify biodiesel in standard diesel-biodiesel blends and samples adulterated with vegetable oil through UV–visible spectroscopy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)An alternative method is proposed for the quantitative analysis of biodiesel in diesel-biodiesel blends. It is based on ultraviolet visible (UV-Vis) spectroscopy and applies univariate calibration, in which the wavelength at 356 nm is considered. Statistical comparisons between the results obtained from the method proposed here and from the infrared (IR) spectrometry method (EN 14078) show that the UV Vis method offers equivalent results compared with the standard one. Furthermore, the alliance between the UV Vis technique and partial least squares (PLS) provides the quantification of biodiesel in blends adulterated with vegetable oil. It means that the UV Vis PLS model can recognize the difference between biodiesel and vegetable oil, whereas the univariate methods, either UV Vis or IR, cannot. Therefore, the methods developed to quantify biodiesel in blends are proposed as more practical and simpler alternatives to the official method. (C) 2016 Elsevier Ltd. All rights reserved.An alternative method is proposed for the quantitative analysis of biodiesel in diesel-biodiesel blends. It is based on ultraviolet–visible (UV–Vis) spectroscopy and applies univariate calibration, in which the wavelength at 356 nm is considered. Statisti186199203CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)sem informaçãoThe authors are grateful to CNPq for financial suppor

A Simple, Fast, And Green Titrimetric Method For The Determination Of The Iodine Value Of Vegetable Oils Without Wijs Solution (icl)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)A simple titrimetric method for the determination of the iodine value of vegetable oils is proposed. Water is used as the principal solvent, and ethanol is employed to dissolve the oil samples and to prepare a standard iodine solution. The determinations made by the proposed method were compared with the procedure described in the American Oil Chemists' Society Cd-1-25 method, which is essentially the Wijs method and uses Wijs solution (ICl). Vegetable oils from 15 different sources were analyzed using the two methods, and a statistical comparison between them showed that both methods offer equivalent results and precision. As advantages, the proposed procedure is simpler, faster, greener (with significantly less toxic chemicals), and of lower cost (ten times cheaper) compared with the Wijs method.9924792483Brazilian National Counsel of Technological and Scientific Development, CNPq, Brasilia, BrazilCoordination for the Improvement of Higher Education Personnel, CAPES, Brasilia, BrazilConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Simple Methods via Mid-IR or 1

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Two methods for determining the iodine value in vegetable oils are described. One employs mid-infrared (mid-IR) spectroscopy and the other uses hydrogen nuclear magnetic resonance (H-1 NMR). The determination of the iodine value is based on either the transmittance intensity of mid-IR signals or on the H-1 NMR signal integration and multivariate calibration. Both of the methods showed adequate coefficients of determination (r(2) = 0.9974 and 0.9978, respectively) when compared to Wijs method, which is recommended by the norm EN 14111. A statistical comparison between the results from the proposed methods and from Wijs method shows that both instrumental methods offer equivalent results and greater precisions compared to Wijs method. The regressions obtained from the constructed models were considered statistically significant and useful for making predictions. The proposed methods present several advantages compared to Wijs method because they significantly reduce analysis time, reagent consumption and waste generation. Furthermore, an analyst can choose between the mid-IR or H-1 NMR to determine the iodine value.Two methods for determining the iodine value in vegetable oils are described. One employs mid-infrared (mid-IR) spectroscopy and the other uses hydrogen nuclear magnetic resonance (1H NMR). The determination of the iodine value is based on either the tran26714311437FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)sem informaçãosem informaçãoThe authors are grateful to CNPq and FAPESP for financial support. The authors also thank the Laboratory of Extraction, Applied Thermodynamics and Equilibrium (Faculty of Food Engineering, Unicamp) for the donated oil

Use of Portable X-ray Fluorescence to Discriminate Brands of Nail Polishes: a Potential Forensic Tool

In forensic analysis, a small quantity of a particular material (hairs, fibers, soils, glasses, paints, among others) can be important to elucidate the sequence of events in a crime scene or to establish the relationship among subjects and facts. There are several examples of cosmetics used as forensic evidences, such as lipsticks and nail polishes. The composition of nail polishes varies according to brand, color and purpose of the product. In this work, the separation of Brazilian nail polishes according to their brand was evaluated using a portable energy dispersive X-ray fluorescence spectrometer (EDXRF) and principal component analysis (PCA). The nonsupervised classification of five brands indicates that the proposed methodology may be a quick, low cost and green alternative to discriminate brands and other characteristics related to a nail polish sample, as possible evidence in crime scenes

Influence of pluronic F127 microenvironments on the photochemical nitric oxide release from S-nitrosoglutathione

Poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) (F127) hydrogels have been used to deliver nitric oxide (NO) topically in biomedical applications. Here, the effect of F127 microenvironments on the photochemical NO release from S-nitrosoglutathione (GSNO) was investigated in F127 solutions 7.6 wt% 15 wt% and 22.5 wt% at 15 C and 37 C. Small-angle X-ray Scattering (SAXS) and Differential Scanning Calorimetry (DSC) measurements, along with proton Nuclear Magnetic Resonance (1H NMR) spectral shifts and T2 relaxation data at six different concentration-temperature conditions, allowed identifying F127 microphases characterized by: a sol phase of unimers; micelles in non-defined periodic order, and a gel phase of cubic packed micelles. Kinetic measurements showed that GSNO photodecompositon proceeds faster in micellized F127 where GSNO is segregated to the intermicellar microenvironment. Real time kinetic monitoring of NO release and T2 relaxation profiles showed that NO is preferentially partitioned into the hydrophobic PPO cores of the F127 micelles, with the consequent decrease in its rate of release to the gas phase. These results show that F127 microphases affect both the kinetics of GSNO photodecomposition and the rate of NO escape and can be used to modulate the photochemical NO delivery from F127/GSNO solutions.544217229FAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo2017/19253-7; 2014/03266-4; 2013/07173-8; 2017/04615-

Phytosterols and γ-Oryzanol as Cholesterol Solid Phase Modifiers during Digestion

Literature reports that ingestion of phytosterols and γ-oryzanol contributes to cholesterol lowering. Despite in vivo observations, thermodynamic phase equilibria could explain phenomena occurring during digestion leading to such effects. To advance the observations made by previous literature, this study was aimed at describing the complete solid–liquid phase equilibrium diagrams of cholesterol + phytosterol and γ-oryzanol systems by DSC, evaluating them by powder X-ray, microscopy, and thermodynamic modeling. Additionally, this study evaluated the phenomena observed by an in vitro digestibility method. Results confirmed the formation of solid solution in the cholesterol + phytosterols system at any concentration and that cholesterol + γ-oryzanol mixtures formed stable liquid crystalline phases with a significant melting temperature depression. The in vitro protocol supported the idea that the same phenomena can occur during digestion in which mechanochemical forces were probably the mechanisms promoting cholesterol solid phase changes in the presence of such phytocompounds. In this case, these changes could alter cholesterol solubility and possibly its absorption in the gastrointestinal lumen