This laboratory experiment, designed for undergraduate nonmajors or advanced high school students, attempts to demystify the technique of spectrophotometry by utilizing a hands-on, real-world approach. Modification of the reaction for the formation of Fe[(bpy)[subscript 3]][subscript 2+] allows students to interact with vitamin C, a compound with…

Experiments in laboratory manuals intended for general, organic, and biological (GOB) chemistry laboratories include few opportunities for students to engage in instrumental methods of analysis. Many of these students seek careers in modern health-related fields where experience in spectroscopic techniques would be beneficial. A simple, rapid,…

Experimental procedures are provided for the quantitative determination of Vitamin A (retinol) in food products by analytical liquid chromatography. Standard addition and calibration curve extraction methods are outlined. (SK)

Reactive oxygen species such as singlet oxygen have been a major focus of research in medicine. The effect of singlet oxygen on sterols within biological membranes is becoming increasingly more important. Ergosterol, a vitamin D precursor, is one such sterol. The benzoylation of ergosterol and subsequent reaction with singlet oxygen to form an…

This article describes an undergraduate electrochemistry laboratory experiment in which the students measure the L-ascorbic acid content of a real sample. Gold electrodes modified with self-assembled monolayers (SAMs) of thioctic acid and cysteamine are prepared to study the effects of surface modification on the electrode reaction of L-ascorbic…

Describes an experiment in which the iron content of a commercial vitamin tablet is determined by comparing its visible spectrum to the visible spectrum of a standardized iron solution. (MLH)

Provides procedures for synthesizing and purifying a vitamin K metabolite (2,3-epoxide) to introduce many of the techniques used in lipid biochemistry. Includes typical results obtained as well as an optional experiment designed to test the purity of the epoxide obtained. (JM)

Discusses reactions of free radicals that determine the chemistry of many fresh, processed, and stored foods. Focuses on reactions involving ascorbic acid, myoglobin, and palmitate radicals as representative radicals derived from a vitamin, metallo-protein, and saturated lipid. Basic concepts related to free radical structure, formation, and…

Energy drinks, as familiar consumer products, have been widely used in laboratory courses to help promote student interest, as well as to connect lecture concepts with laboratory work. Energy drinks contain B vitamins: pyridoxine (vitamin B6) and riboflavin (vitamin B2) of which amounts are high enough to be of concern. In this work, a fast and…

Described is an experiment used in an undergraduate biochemistry laboratory involving inducing rickets in chicks and correlating the disease to a reduction in vitamin D-dependent calcium binding protein. Techniques involved are hormone induction, protein isolation, and radioisotope methodology. (Author/DS)

To prove that oxygen is irreversibly consumed in the blue bottle reaction, a manometer or a plastic bottle was used to show a permanent reduction in the gas pressure in a reaction vessel. This demonstration may be misleading because the change in gas pressure can be attributed to a number of other factors such as temperature change and involvement…

During the COVID-19 pandemic, many colleges switched to online or hybrid formats for both lecture and laboratory course delivery. While virtual experiments, that is, "dry lab" experiences, teach students chemical theory, it is essential for students in chemistry laboratories to participate in hands-on laboratory activities. These…

Quantification of the many constituents that make up our food, whether they are desirable (vitamins, antioxidants, nutrients) or undesirable (pesticides, toxins), is one of the most practical applications of chemistry. In this study, kombucha, a popular fermented tea beverage, was analyzed using acid-base titration and high-performance liquid…

An engaging and colorful demonstration was developed that illustrates the utility of resonance theory in predicting the relative acidities of alcohols. The demonstration can be used as an introduction to exercises that provide students with practice in writing resonance structures and in predicting relative acidities. The demonstration exploits…

Many small-molecule antioxidants found in whole fruits and vegetables are analyzed and identified in this laboratory module for upper-division biochemistry courses. During this experiment, students develop their knowledge of the bioactivity of fruit and vegetable products while learning techniques to identify vitamins and nutritionally derived…