Portable mass spectrometers provide a unique opportunity to obtain in situ measurements. This minimizes need for sample collection or in laboratory analysis. Membrane Inlet Mass Spectrometry (MIMS) utilizing a semi permeable membrane for selective rapid introduction for analysis. Polydimethylsiloxane membranes have been proven to be robust in selecting for aromatic chemistries. Advances in front end design have allowed for increased sensitivity, rapid sample analysis, and on line measurements. Applications of the membrane inlet technique have been applied to environmental detection of clandestine drug chemistries and pollutants. Emplacement of a mass spectrometer unit in a vehicle has allowed for large areas to be mapped, obtaining a rapid snapshot of the various concentrations and types of environmental pollutants present. Further refinements and miniaturization have allowed for a backpackable system for analysis in remote harsh environments. Inclusion of atmospheric dispersion modeling has yielded an analytical method of approximating upwind source locations, which has law enforcement, military, and environmental applications. The atmospheric dispersion theories have further been applied to an earth based separation, whereby chemical properties are used to approximate atmospheric mobility, and chemistries are further identified has a portable mass spectrometer is traversed closer to a point source.

Four isosteric series of plant growth-regulating compounds were prepared. Using an Avena sativa coleptile assay system, derivatives in series I and IV inhibited segment elongation to a greater degree than did comparable derivatives in series II and III.

A rapidly growing topic of great interest is the adaptation of benchtop analytical instrumentation for use in outdoor harsh environments. Some of the areas that stand to benefit from field instrumentation development include government agencies involved with the preservation of the environment and institutions responsible for the safety of the general public. Detection systems are at the forefront of the miniaturization movement as the interest in analyte identification and quantitation appears to only be accessible through the use of analytical instrumentation. Mass spectrometry is a distinguished analytical technique known for its ability to detect the mass-to-charge (m/z) ratios of gas-phase ions of interest. Although these systems have been routinely limited to research lab-based analysis, there has been considerable development of miniaturized and portable mass spectrometry systems. Membrane Inlet Mass Spectrometry (MIMS) is becoming a common method of sample introduction that is subject to significant development. MIMS allows for minimal sample preparation, continuous sampling, and excludes complicated analyte introduction techniques. Sampling is accomplished using a semipermeable membrane that allows selective analyte passage into the vacuum of the mass spectrometer. MIMS is becoming the preeminent choice of homeland security and environmental monitoring applications with increasing opportunities for the future development of specialized …