Approaching Diesel Fuel Quality in Chemistry Lab Classes: Undergraduate Student’s Achievements on Determination of Biodiesel Content in Diesel Oil Applying Solvatochromic Effect

Santos, Rafael Cavalcante dos; Cavalcanti, Juliane Natalizi Cabral; Carmo, Elisa Carneiro Werneck do; Souza, Fernando Costa de; Soares, Wesley Garcia; Souza, Cristiane Gimenes de; Andrade, Débora França de; d’Avila, Luiz Antonio

doi:10.1021/acs.jchemed.0c00773

Cited by 7 publications

(4 citation statements)

References 35 publications

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“…In 2020−2021, some laboratory experiments were carried out using digital images. We could cite polymer degradation, 12 determination of iron(III) in water, 13 calculation of food dye adsorption isotherms, 14 quantitative analysis of food dyes, 15 determination of biodiesel content in diesel oil, 16 the analysis of salivary amylase using starch from food as a substrate, 17 and determination of starch in banana. 18 Pol et al 2 quantified nitrite in surface water using the Griess assay and digital images obtained using a smartphone.…”

Section: ■ Introductionmentioning

confidence: 99%

Quantification of Nitrite in Food and Water Samples Using the Griess Assay and Digital Images Acquired Using a Desktop Scanner

Filgueiras¹,

Jesus²,

Borges³

2021

J. Chem. Educ.

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The Griess assay is widely used by regulation agencies as an official method for nitrite quantification in water and food samples. In Brazil, the official method, which has been used to determine nitrite in food, was described by Instituto Adolfo Lutz (283/IV) in 1984. It uses 8 mL of reactants and provides 50 mL (reactants plus sample) of waste per sample analyzed. Here, students scaled down the official method 50 times and quantified nitrite in water and food samples by using just 0.2 mL of the Griess reactant and 1 mL of sample. Quantitative analysis was carried out using absorbance measured at 540 nm (standard method) and 96-well-plate images (proposed method) obtained with a desktop scanner. The nitrite was extracted from solid food samples by heating it in a water bath. After heating, sample color and turbidity were eliminated by addition of K4[Fe(CN)6] and ZnSO4 solutions and filtering. During samples preparation, students evaluate the heating time effect in nitrite extraction from sausage samples using hypothesis tests. Students did a series of matrix matched samples to observe the matrix effect. Students also calculated the detection limit (DL) and the quantification limit (QL) for the proposed method (1.35 and 4.1 μmol/L nitrite, respectively) and for the standard method (1.1 and 3.4 μmol/L nitrite, respectively). DL and QL were determined using the standard deviation of the lowest concentration point on the standard curve. The major pedagogical value of this laboratory class was to scale down the official method and use it to prepare and analyze a solid food sample. As a learning model, finding real water samples, which have nitrite concentrations larger than method QL, was a hard task, but all sausage samples analyzed had larger nitrate concentrations than the method QL and nitrite quantification in sausages was a good learning model.

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Section: ■ Introductionmentioning

confidence: 99%

Quantification of Nitrite in Food and Water Samples Using the Griess Assay and Digital Images Acquired Using a Desktop Scanner

Filgueiras¹,

Jesus²,

Borges³

2021

J. Chem. Educ.

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“…A comment regarding the contribution of the present project is in order. BD was the subject of several papers, including chemical education-related publications. ,,− The emphasis was, e.g., on the synthesis procedure, ,,− analysis of BD and its blend with (mineral) diesel oil using FTIR, HPLC, 1 H NMR, and UV–vis (using solvatochromic dyes), ,− and the properties of BD as fuel . The oils employed included fresh and recycled vegetable oils as well as those from other sources, e.g., algal lipids and Jojoba oil .…”

Section: Resultsmentioning

confidence: 99%

Active Learning in the Undergraduate Chemistry Laboratory: Synthesis of Biodiesel from an Amazon Region Oil (Babassu): Keep It Simple!

et al. 2023

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An active-learning approach was employed in a project for our chemistry major students on the synthesis of biodiesel (BD) from an Amazon region oil. The project, involving activities in class and in the laboratory, was given during 8 weeks of the spring semester of 2022. The students were asked about their previous contact with the synthesis and analysis of BD, ionic liquids as solvents and catalysts, and the use of chemometrics for yield optimization. The students were asked to do a literature survey, suggesting renewable starting materials (oil and alcohol) and a homogeneous catalyst for BD synthesis. The students selected babassu oil, bioethanol, and a Brønsted acid as a taskspecific ionic liquid catalyst. As independent experimental variables, the students suggested studying the effects of reaction mixture composition (oil, alcohol, catalyst) and reaction time and temperature. Based on a second questionnaire, the students chose viscosity for the determination of the BD yield. By using design of experiment and varying the molar ratios of bioethanol/babassu oil (6−12) and catalyst/babassu oil (0.1−0.2) and reaction time (1−2 h), the students calculated the effect of these variables on BD yield. The resulting mathematical correlations were validated by using additional experiments. Measuring product viscosity, after its appropriate purification, is a simple and attractive alternative to gas chromatography, being less time-and energy-consuming. The students positively evaluated the project because of the socioeconomic importance of BD, the use of renewable starting materials, application of chemometrics for yield optimization, and they were involved in decision making.

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“…The advantages of this method are portability, simplicity, low cost, and ease of operation. The achievements of these smartphonebased spectrophotometric methods have been widely reported in various fields, such as agriculture (Jin et al, 2021;Qi et al, 2020), education (Kajornklin et al, 2020;Santos et al, 2020), the environment (Koohkan et al, 2020;Sargazi & Kaykhaii, 2020), food (Peamaroon et al, 2021;Ko et al, 2021), forensic science (Li et al, 2020;Jackson et al, 2020), industry (Moonrungsee et al, 2020;Shahvar et al, 2020), medical diagnostics (Samacoits et al, 2021;Kap et al, 2021), and pharmaceuticals (Phadungcharoen et al, 2020;Lantam et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

A Simple 3d Toolbox-Based Smartphone Colorimeter: The Ability to Detect the Stoichiometric Equivalent of a Chemical Reaction

Moonrungsee,

Jakmunee,

Boonmee

et al. 2023

MJS

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The simple 3D toolbox is constructed and used with a smartphone for detecting the stoichiometric equivalent of chemical reactions. The reaction between salicylic acid and iron(III) ion to form a purple complex is chosen. The captured image of the purple product is measured for RGB color intensities. The color intensities of the solutions depends on concentration of the colored product, and the constant color intensities were observed after the reaction reached its stoichiometry. Several smartphones have been tested for capturing the images and measuring the color intensities. It revealed that all smartphones can be used but the white balance mode is required tuning up to get clear enough picture for color intensity measurement. This smartphone spectrometer provides a comparable results to those obtained from a commercial ultraviolet-visible spectrometer. This work can be a guideline for creation of portable devices in chemical analysis using a smartphone. Moreover, the developed device and method can be practically repeated in chemistry laboratory class for teaching stoichiometry and chemical reaction using a smartphone.

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Approaching Diesel Fuel Quality in Chemistry Lab Classes: Undergraduate Student’s Achievements on Determination of Biodiesel Content in Diesel Oil Applying Solvatochromic Effect

Cited by 7 publications

References 35 publications

Quantification of Nitrite in Food and Water Samples Using the Griess Assay and Digital Images Acquired Using a Desktop Scanner

Quantification of Nitrite in Food and Water Samples Using the Griess Assay and Digital Images Acquired Using a Desktop Scanner

Active Learning in the Undergraduate Chemistry Laboratory: Synthesis of Biodiesel from an Amazon Region Oil (Babassu): Keep It Simple!

A Simple 3d Toolbox-Based Smartphone Colorimeter: The Ability to Detect the Stoichiometric Equivalent of a Chemical Reaction

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