Discusses the nature of Fourier transform mass spectrometry and its unique combination of high mass resolution, high upper mass limit, and multichannel advantage. Examines its operation, capabilities and limitations, applications (ion storage, ion manipulation, ion chemistry), and future applications and developments. (JN)

Reviews applications of laser methods to analytical problems, selecting examples from multiphoton ionization and fluorescence analysis. Indicates that laser methodologies promise to improve dramatically the detection of trace substances embedded in "real" matrices, giving the analyst a most powerful means for determining the composition of…

Examines the controversy surrounding the validity and interpretation of electron microscope images. (DS)

The design and use of an inexpensive thermistor thermometer is described. In addition to providing a rugged thermometer, using the instruments offers an opportunity to have students become familiar with new principles and techniques, such as principles of thermistors, the Wheatstone bridge, and the concept of calibration. (JN)

Background information, procedures, and results are provided for an experiment in which students: (1) construct an immobilized penicillinase electrode; (2) evaluate electron response as a function of penicillin concentration; and (3) study effects of solvent compositions, ionic strength, and equilibrium time upon electrode response. (JN)

Reviews trends in liquid chromatography including apparatus, factors affecting efficient separation of a mixture (peak sharpness and speed), simplified problem-solving, adsorption, bonded phase chromatography, ion selectivity, and size exclusion. The current trend is to control chemical selectivity by the liquid phase. (Author/JN)

Use of gradient elution techniques in high performance liquid chromatography (HPLC) is often essential for direct separation of complex mixtures. Since most commercial controllers have features that are of marginal value for instructional purposes, a low-cost controller capable of illustrating essential features of gradient elution was developed.…

Describes an inexpensive means for determining proximate analysis of coal, and by use of this data, its energy content. Pyrite content is also obtained by utilizing magnetic properties of iron. The simple device used makes the experiment suitable for the undergraduate laboratory. (Author/JN)

The use of green, red, and far-red light-emitting diodes (LEDs) as light sources for plant physiological studies is outlined and evaluated. Indicates that LED lamps have the advantage over conventional light sources in that they are lightweight, low-cost, portable, easily constructed, and do not require color filters. (Author/DH)

Discusses: (1) rationale for chemical sensors in process analysis; (2) existing types of process chemical sensors; (3) sensor limitations, considering lessons of chemometrics; (4) trends in process control sensors; and (5) future prospects. (JN)

Described is a simple apparatus to determine acceleration due to gravity. It utilizes direct contact switches in lieu of conventional photocells to time the fall of a ball bearing. Accuracies to better than one part in a thousand were obtained. (SL)

By using intense pulsed coherent x-ray sources it will be possible to obtain magnified three-dimensional images of living elementary biological structures at precisely defined instants. Discussed are sources/geometrics for x-ray holography, x-radiation interactions, factors affecting resolution, recording the hologram, high-intensity holography,…

Standing transverse waves in homogeneous strings have been demonstrated in lectures and used in experiments (called Melde's experiment). A variation to this experiment is discussed. Also discusses the use of the speed-of-sound resonance-tube apparatus to clean mercury. (Author/JN)

Background information procedures and results are provided for a diffusion (permeation) experiment using an inexpensive instrument and performed during a single three-hour laboratory period. (JN)

Describes the mechanism of bicycle computers functioning as speedometers and timers. Discusses why the computers do not display the continuously changing readings and show the correct values at higher speeds. (YP)