Describes sensitive and specific methods used to monitor tetrachlorodibenzodioxins and tetrachlorodibenzofurans. The procedures are suitable for detecting and quantifying these substances at the parts-per-trillion levels in complex environmental and biological samples. (Author/JN)

Free radical chlorination of methane is used in organic chemistry to introduce free radical/chain reactions. In spite of its common occurrence, demonstrations of the reaction are uncommon. Therefore, such a demonstration is provided, including background information, preparation of reactants/reaction vessel, introduction of reactants, irradiation,…

Reviews graphical methods for representing ternary and quaternary systems, focusing on use of triangular composition diagrams. Examines some of the relevant geometry of triangles in general, showing that right isosceles triangles possess some very advantageous features for representing ternary systems. (JN)

Describes an experiment on the qualitative analysis of several over-the-counter analgesic tablets. Background information, procedures used (including high pressure liquid chromatography), and typical student results are included. (JN)

A Beckmann arrangement was developed which explores the concept of stereospecificity and concurrently exposes students to synthetic, spectrophotometric, and chromatographic processes. Background information, laboratory procedures, and results are provided. (JN)

Hydantoins are a drug family lying within the broadly related ureide structural frame which encompasses many of the anticonvulsant drugs used in treatment of various types of epilepsy. Background information and experimental procedures are provided for the synthesis of the hydantoin 5,5-diphenylhydantoin. (JN)

Discusses use of 1,1,1-trichloroethane as a substitute for carbon tetrachloride. Provides information on additives to commercially supplied sources in relation to possible reaction interferences. Warns of toxicity and possible carcinogenic action. (JM)

Describes a three-hour experiment designed to introduce students to chemistry of the angiotensis-converting enzyme, illustrate design of a quenched fluorescence substrate, and examine considerations necessary in designing a clinical assay. Includes background information on the biochemistry of hypertension, reagents/materials needed, procedures…

Cyclic voltammetry is a simple experiment that has become popular in chemical research because it can provide useful information about redox reactions in a form which is easily obtained and interpreted. Discusses principles of the method and illustrates its use in the study of four electrode reactions. (Author/JN)

Describes modification of a chemical reaction to a single 4 1/2-hour laboratory period. Reaction kinetics between 2, 4-initrochlorobenzene and piperidine to form 2, 4-dinitrophenyl-piperidine and piperidinium hydrochloride are followed conductometrically at three temperatures to obtain data to calculate activation parameters. (Author/JN)

Effect of the "polarity" of low-polarity solvents on the amount of swelling produced in a solid polymer (demonstrated in an organic chemistry lecture) is also suitable as a laboratory experiment. Students can be assigned to a small group of solvents from the list provided. Procedures and materials needed are included. (Author/JN)