Describes a laboratory experiment that is designed to aid in the understanding of the fundamental process involved in gas chromatographic separations. Introduces the Kovats retention index system for use by chemistry students to establish criteria for the optimal selection of gas chromatographic stationary phases. (TW)

Describes procedures involved with paper electrophoresis separation of amino acids, gel electrophoresis separation of DNA, and design of an electrophoresis tank. Describes experiments using paper (amino acids) and gel (deoxyribonucleic acid fragments). Provides material lists, procedures, and discussion. (JM)

Discusses a student exercise which requires the optimizing of the charring and atomization temperatures by producing a plot of absorbance versus temperature for each temperature parameter. Notes that although the graphite furnace atomic absorption spectroscopy technique has widespread industrial use, there are no published, structured experiments…

Gives upper level chemistry students a better understanding of the application of lasers in the field of spectroscopy. Provides three experiments to demonstrate the thermal lens effect: determination of beam profile, cell position optimization, and pKa determination. (MVL)

Presents a practical and attractive alternative to the sand bath used in the microscale procedures developed by Mayo, Pike, and Butcher. Urges the organic chemistry teaching community to continue towards complete conversion to microscale techniques. Presents the use of aluminum devices in the microlaboratory. (MVL)

Notes the careful observation of chemical reactivity phenomena has been and should be an important part of the general chemistry laboratory curriculum. Stresses reduction of experimental scale will help to ensure, in times of rampant chemophobia, that it remains so. Provides several examples of the methodology. (MVL)

Presents a halogen substitution of an alkane using a compartmentalized Petri dish or Conway dish on an overhead projector. Provides methodology and several modifications for different reactions. Uses hexane, methyl orange, bromine, and silver nitrate. (MVL)

Explores the structural behavior of polyenic pi systems such as isomerization and conjugation. Uses the simultaneous spectrophotometric analysis of a beta-carotene and lycopene mixture. Presents an empirical method to determine the number of double bonds in the polyenic carotenoid. (MVL)

Discusses electron spin resonance, a form of magnetic resonance spectroscopy, used to study electronic structure of molecules with unpaired electrons. Studies benzosemiquinone radical anions which are long-lived and inexpensive. Uses a Project SERAPHIM computer program to perform a Huckel molecular orbital calculation. (MVL)