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Journal Articles: 22 results
"As Simple as Possible, but Not Simpler"—The Case of Dehydroascorbic Acid  Robert C. Kerber
Textbooks routinely assign dehydroascorbic acid a tricarbonyl structure that is highly improbable in aqueous solution and inconsistent with its colorless appearance. Studies of oxidized forms of ascorbic acid are summarized here, and a plea is entered for accurate descriptions of chemical structures in this and other cases, even at the cost of some simplicity.
Kerber, Robert C. J. Chem. Educ. 2008, 85, 1237.
Bioorganic Chemistry |
Free Radicals |
Natural Products |
NMR Spectroscopy |
Vitamins
Radical Quenching of 1,1-Diphenyl-2-picrylhydrazyl: A Spectrometric Determination of Antioxidant Behavior  John M. Berger, Roshniben J. Rana, Hira Javeed, Iqra Javeed, and Sandi L. Schulien
Describes a colorimetric assay using the persistent radical 1,1-diphenyl-2-picrylhydrazyl to measure the activity of common antioxidants. This exercise is particularly appropriate for a course geared for nutrition or food science majors.
Berger, John M.; Rana, Roshniben J.; Javeed, Hira; Javeed, Iqra; Schulien, Sandi L. J. Chem. Educ. 2008, 85, 408.
Food Science |
Free Radicals |
UV-Vis Spectroscopy |
Vitamins
The Stereochemistry of Biochemical Molecules: A Subject to Revisit  Josep J. Centelles and Santiago Imperial
This article reports on errors in stereochemistry of complex hydrosoluble vitamin B12 molecule. Twenty-five popular biochemistry textbooks were examined for their treatment of the stereoisomery of vitamin B12. Mistakes, discrepancies, and oddities reported in vitamin B12 are just an example of this problem. Biochemistry textbook authors and teachers should pay more attention to the stereoisomery of biochemical molecules to avoid studentsĀ confusion.
Centelles, Josep J.; Imperial, Santiago. J. Chem. Educ. 2005, 82, 75.
Stereochemistry |
Vitamins
Studying Current–Potential Curves Using Bipotentiometric Iodometric Back-Titration for the Determination of Ascorbic Acid in Fruits and Vegetables  Roxana A. Verdini and Claudia M. Lagier
A method for the determination of the ascorbic acid content in fruits and vegetables was used to introduce the principles of voltammetry. The procedure combines an iodometric back-titration with voltammetric (bipotentiometric) end point detection, which minimizes the risk of ascorbic acid oxidation, allowing for a rapid and efficient quantification of vitamin C in fruits and vegetables. A better understanding of the titration curve is achieved by analyzing the schematic currentĀpotential curves of the anodic and cathodic half-cell reactions during the titration.
Verdini, Roxana A.; Lagier, Claudia M. J. Chem. Educ. 2004, 81, 1482.
Constitutional Isomers |
Electrochemistry |
Food Science |
Instrumental Methods |
Oxidation / Reduction |
Titration / Volumetric Analysis |
Vitamins |
Consumer Chemistry
Microscale Determination of Vitamin C by Weight Titrimetry  Gaston A. East and Erica C. Nascimento
Electroanalytical method for the microscale determination of vitamin C using a nontraditional oxidimetric titrant.
East, Gaston A.; Nascimento, Erica C. J. Chem. Educ. 2002, 79, 100.
Electrochemistry |
Instrumental Methods |
Microscale Lab |
Quantitative Analysis |
Vitamins |
Titration / Volumetric Analysis |
Oxidation / Reduction
UV-Visible First-Derivative Spectrophotometry Applied to an Analysis of a Vitamin Mixture  F. Aberásturi, A. I. Jiménez, F. Jiménez, and J. J. Arias
A simple experiment that uses UV-vis spectrophotometry to introduce undergraduate chemistry students to multicomponent analysis and a method for the simultaneous determination of three vitamins using derivative spectrophotometry (zero-crossing method).
Aberásturi, F.; Jiménez, A. I.; Jiménez, F.; Arias, J. J. J. Chem. Educ. 2001, 78, 793.
Undergraduate Research |
UV-Vis Spectroscopy |
Vitamins |
Quantitative Analysis
Iron as Nutrient and Poison  N. M. Senozan and M. P. Christiano
Iron containing compounds of the body and the ingestion and elimination of iron, the function and transport of this metal among different sites and substances of the body, and biochemical defects and nutritional habits that lead to excessive accumulation of iron and some unexpected consequences of this accumulation are described.
Senozan, N. M.; Christiano, M. P. J. Chem. Educ. 1997, 74, 1060.
Bioinorganic Chemistry |
Bioorganic Chemistry |
Food Science |
Metals |
Vitamins |
Toxicology |
Nutrition |
Applications of Chemistry |
Descriptive Chemistry
Improving a Microscale Vitamin C Laboratory  Helser, Terry L.
Procedure for increasing the stability of vitamin C samples and titrating dye for titrations.
Helser, Terry L. J. Chem. Educ. 1995, 72, A10.
Titration / Volumetric Analysis |
Vitamins |
Laboratory Management |
Microscale Lab
Determination of the effect of various modes of cooking on the vitamin C content of a common food, green pepper: An introductory biochemistry experiment  Johnson, Eric R.
A great laboratory experiment that examines the effects of baking, boiling, steaming, and microwaving a green pepper on the pepper's nutritional level.
Johnson, Eric R. J. Chem. Educ. 1988, 65, 926.
Nutrition |
Titration / Volumetric Analysis |
Vitamins |
Food Science |
Applications of Chemistry
Analysis of vitamin C by high-pressure liquid chromatography  Goodney, David E.
Using HPLC to determine the concentration of vitamin C in a variety of juices.
Goodney, David E. J. Chem. Educ. 1987, 64, 187.
Vitamins |
HPLC |
Separation Science |
Quantitative Analysis
Tomato juice rainbow: A colorful and instructive demonstration  MacBeath, Marie E.; Richardson, Andrew L.
When saturated bromine water is gently stirred into canned tomato juice, a concentration gradient occurs and produces a colorful effect.
MacBeath, Marie E.; Richardson, Andrew L. J. Chem. Educ. 1986, 63, 1092.
Food Science |
Bioorganic Chemistry |
Vitamins
High performance liquid chromatography of vitamin A  Bohman, Ove; Engdahl, Kjell-Ake; Johnsson, Hakan
This experiment involves the quantitative determination of vitamin A in food products by analytival liquid chromatography and offers training both in work-up procedures and in the quantitative transfer of very small amounts of material.
Bohman, Ove; Engdahl, Kjell-Ake; Johnsson, Hakan J. Chem. Educ. 1982, 59, 251.
HPLC |
Chromatography |
Vitamins |
Quantitative Analysis |
Esters |
Fatty Acids
Determination of iron by atomic absorption in vitamin-mineral tablets  Pinnell, Robert P.; Zanella, Andrew W.
A description for a laboratory for use in quantitative analysis in which iron in multivitamin tables is determined by atomic absorption.
Pinnell, Robert P.; Zanella, Andrew W. J. Chem. Educ. 1981, 58, 444.
Consumer Chemistry |
Quantitative Analysis |
Atomic Spectroscopy |
Vitamins
Excretion of ingested ascorbic acid: An easy, interesting undergraduate experiment  Sirota, G. R.; MacInnis, W. K.; Rasmussen, P. W.
The student ingests ascorbic acid and then measures the amount excreted in his urine using a microfluorometric procedure.
Sirota, G. R.; MacInnis, W. K.; Rasmussen, P. W. J. Chem. Educ. 1979, 56, 421.
Carboxylic Acids |
Vitamins |
Quantitative Analysis
Vitamin C content of commercial orange juices. An analytical project  Haddad, Paul
Studying the magnitude and stability of the ascorbic acid content of commercial orange juices; students were interested in ascertaining if orange juice represents a suitable source of Vitamin C after one or two weeks in the refrigerator.
Haddad, Paul J. Chem. Educ. 1977, 54, 192.
Vitamins |
Quantitative Analysis |
Consumer Chemistry |
Applications of Chemistry |
Toxicology
Colorimetric determination of iron in vitamin supplement tablets. A general chemistry experiment  Atkins, Robert C.
The basic concepts of instrumental analysis are introduced through modification of a standard procedure for the colorimetric determination of iron.
Atkins, Robert C. J. Chem. Educ. 1975, 52, 550.
Vitamins |
Quantitative Analysis |
Consumer Chemistry
Analysis of commercial vitamin C tablets by iodometric and coulometric titrimetry  Marsh, Daniel G.; Jacobs, Deborah L.; Veening, Hans
The ascorbic acid content of vitamin C tablets is determined iodometrically using a back titration with standard thiosulfate; ascorbic acid is then titrated coullometrically by direct oxidation to dehydroascorbic acid using electrolytically generated bromine.
Marsh, Daniel G.; Jacobs, Deborah L.; Veening, Hans J. Chem. Educ. 1973, 50, 626.
Vitamins |
Titration / Volumetric Analysis |
Oxidation / Reduction |
Electrochemistry
Vitamin C and the diet of a student  Fulkrod, John E.
Determining the ascorbic acid in urine.
Fulkrod, John E. J. Chem. Educ. 1972, 49, 738.
Vitamins |
Applications of Chemistry |
Nonmajor Courses |
Quantitative Analysis
Questions [and] Answers  Campbell, J. A.
Six questions requiring an application of basic principles of chemistry. [Debut]
Campbell, J. A. J. Chem. Educ. 1972, 49, 5.
Enrichment / Review Materials |
Vitamins |
Alcohols |
Oxidation / Reduction
A simple laboratory experiment on PVP column chromatography  Lerner, Joseph
This experiment deals with the separation of three colored biochemicals, two of which are vitamins, the other a protein.
Lerner, Joseph J. Chem. Educ. 1970, 47, 32.
Chromatography |
Separation Science |
Vitamins
The laboratory preparation of a simple vitamin: p-aminobenzoic acid  Kremer, Chester B.
Describes the laboratory preparation of a simple vitamin, p-aminobenzoic acid, with beneficial physiological activity.
Kremer, Chester B. J. Chem. Educ. 1956, 33, 71.
Vitamins |
Synthesis
The vitamin C content of wild rose hips  Markham, Sister Clare.; Markham, Sister M. Justin
Describes the extraction and determination of the vitamin C content of wild rose hips.
Markham, Sister Clare.; Markham, Sister M. Justin J. Chem. Educ. 1953, 30, 580.
Vitamins |
Natural Products |
Separation Science |
Quantitative Analysis