Liquid–liquid microextraction in sequential injection analysis for the direct spectrophotometric determination of acid number in biodiesel

Batista, Alex D.; Amais, Renata S.; Rocha, Fábio R.P.

doi:10.1016/j.microc.2015.07.022

Cited by 14 publications

(5 citation statements)

References 19 publications

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“…High acidity can neutralize the basic catalyst; therefore, a larger quantity of catalyst is necessary for the reaction to be efficiently conducted. Moreover, a pronounced acidity affects the thermal stability of the fuel due to intermolecular reactions and causes a corrosive action on the metallic components of the engine [28]. Table 3 shows the physicochemical properties for the soybean biodiesel obtained in the experiments as a fuel for CI engines.…”

Section: Physical and Chemical Characteristics Of Biodiesel As Fuel Fmentioning

confidence: 99%

A New Proposal Using a Turbine in the Reactor with a Cavitation System in the Biodiesel Synthesis

Ferreira

Módolo

Scalon

et al. 2016

Waste Biomass Valor

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The present research investigates the effect of a cavitation system with a turbine in comparison to the vigorous stirring on the process of biodiesel synthesis by the transesterification reaction using oil (triglycerides) and anhydrous ethanol. The proposed cavitation equipment consists of a device that works as a turbine (novelty) and not by a pump. The turbine coupled to cavitation system showed a substantial degree of intensification in comparison to the conventional approach reported in the literature. An ester content of 96.4 % in a 5 min reaction was obtained using conventional approach with vigorous stirring of 9500 rpm and ethanol/oil molar ratio of 8:1 and 1.0 wt% catalyst concentration. An ester content of 98.5 % was obtained using ethanol/oil molar ratio of 6:1, 1.0 wt% catalyst concentration and 60 s reaction by cavitation system with a turbine. The properties analyzed of biodiesel, such as density, viscosity, cetane number, cloud point, cold filter plugging point and flash point are within the limit values established by standard methods.

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Section: Physical and Chemical Characteristics Of Biodiesel As Fuel Fmentioning

confidence: 99%

A New Proposal Using a Turbine in the Reactor with a Cavitation System in the Biodiesel Synthesis

Ferreira

Módolo

Scalon

et al. 2016

Waste Biomass Valor

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show abstract

“…A critical review of ASTM and EN methods suggested that the issue of lower reproducibility in ASTM D664 may be due to variability of electrodes (Knothe, ). Other potential issues reported for potentiometric methods (D664) with high AV samples, such as yellow or brown grease, included high cost, labor intensiveness, and time consumption (Batista et al, ; Figueiredo et al, ; Kovács et al, ).…”

Section: Introductionmentioning

confidence: 99%

A Greener Alternative Titration Method for Measuring Acid Values of Fats, Oils, and Grease

Zhang

Ren

et al. 2019

J Americ Oil Chem Soc

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A greener alternative method is proposed for measuring acid values (AV) of fats, oils, and grease (FOG) based on visual titration. Compared with Official Method Cd 3d-63 of the American Oil Chemists' Society (AOCS), this greener alternative method can eliminate the use of toluene, which in turn reduces toxicity and cost. A total of 44 samples of yellow and brown grease with AV ranging from 0.13 to 170.37 (mg KOH) g −1 were titrated using both methods. The alternative titration method can provide accurate and reliable results to determine the AV of FOG by various statistical analyses including repeatability, linear regression, f-test, t-test, and method accuracy calibration with AOCS Cd 3d-63. This low-cost method can be recommended for routine titration in research and development, and in biodiesel plants for most FOG samples.

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“…These methodologies have been well reported, such as automation tools for handling solutions and pre-treatment of samples 7 . Examples include the coupling of interfaces in flow analysis for pre-treatment of sample such as, gas-liquid (gas diffusion, distillation and hydride generation), liquid-liquid (extraction and dialysis) and liquid-solid (ion exchange, adsorption, precipitation, dissolution and stripping) [8][9][10][11][12][13][14] . The indirect determination of RS in of wine employing the classical Fehling's reaction and flow injection coupled to atomic absorption spectrometry (AAS) was reported by Yebra et al (1993) 15 .…”

Section: Introductionmentioning

confidence: 99%

Spectrophotometric Determination of Reducing Sugar in Wines Employing in-Line Dialysis and a Multicommuted Flow Analysis Approach

Silva

Souza

Paim

et al. 2018

J. Chil. Chem. Soc.

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A multicommuted flow procedure for the spectrophotometric determination of reducing sugars in wine has been developed. A dialysis unit was incorporated in the system to minimize matrix interferences and eliminate the colored compounds of the wine. The oxidation-reduction reaction in an alkaline medium between reducing sugars and the Cu 2+ -Neocuproine complex was employed. The compound formed was monitored at 460 nm. In the proposed procedure, there was a linear response between 0.25 and 4.0 g L -1 reducing sugars (y = (0.36 ± 0.02) + (0.31 ± 0.01) * x, R = 0.9975, n = 6), a coefficient of variance of 2.6% for a reducing sugar solution of 2.0 g L -1 (n = 7), a limit of detection estimated at 0.03 g L -1 , reagent consumption per determination of 0.330, 0.128 and 0.160 mg for neocuproine, CuSO 4 and NaOH, respectively. A sampling throughput of 45 determinations per hour was achieved. The proposed system was applied to wine samples and comparing the results with an AOAC official method no significant difference at a 95% confidence level.

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Liquid–liquid microextraction in sequential injection analysis for the direct spectrophotometric determination of acid number in biodiesel

Cited by 14 publications

References 19 publications

A New Proposal Using a Turbine in the Reactor with a Cavitation System in the Biodiesel Synthesis

A New Proposal Using a Turbine in the Reactor with a Cavitation System in the Biodiesel Synthesis

A Greener Alternative Titration Method for Measuring Acid Values of Fats, Oils, and Grease

Spectrophotometric Determination of Reducing Sugar in Wines Employing in-Line Dialysis and a Multicommuted Flow Analysis Approach

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