A novel gas chromatograph-mass spectrometer (GC-MS) based on a miniature toroidal ion trap mass analyzer (TMS) and a low thermal mass GC is described. The TMS system has an effective mass/charge (m/z) range of 50-442 with mass resolution at full-width half-maximum (FWHM) of 0.55 at m/z 91 and 0.80 at m/z 222. A solid-phase microextraction (SPME) fiber mounted in a simple syringe-style holder is used for sample collection and introduction into a specially designed low thermal mass GC injection port. This portable GC-TMS system weighs <13 kg (28 lb), including batteries and helium carrier gas cartridge, and is totally self-contained within dimensions of 47 X 36 X 18 em (18.5 X 14 X 7 in.). System start-up takes about 3 min and sample analysis with library matching typically takes about 5 min, including time for column cool-down. Peak power consumption during sample analysis is about 80 W. Battery power and helium supply cartridges allow 50 and 100 consecutive analyses, respectively. Both can be easily replaced. An on-board library of target analytes is used to provide detection and identification of chemical compounds based on their characteristic retention times and mass spectra. The GC-TMS can detect 200 pg of methyl salicylate on-column. n-Butylbenzene and naphthalene can be detected at a concentration of 100 ppt in water from solid-phase microextraction (SPME) analysis of the headspace. The GC-TMS system has been designed to easily make measurements in a variety of complex and harsh environments. and toxic industrial chemicals (TICs), is a concern, the ability to rapidly detect and accurately identify such chemicals in harsh environments is of great utility. There is a need for field-portable, selective, and sensitive detectors for military and emergency first-responder operations and for on-site environmental contamination measurement, to mention only a couple of key applications. The development of fieldportable devices directed toward fast, on-site analysis is one of the most active research areas in analytical chemistry.Currently, several approaches for detection of CWAs and TICs are utilized by military personnel, first responders, and environmental scientists. They include dye solubility (detection paper), enzymatic reaction,

No abstract

Aviation fuel is so complex that it is virtually impossible to separate all of the major components of the mixture, much less the minor components. The minor components are typically separated from the major components using preparative techniques (such as solid phase extraction;SPE) and then re-examined by gas chromatography-mass spectrometry (GC-MS). Without SPE, GC-MS is not capable of a comprehensive determination of the trace polar components in jet fuel due to fuel complexity. In this contribution, jet fuel mixtures are preseparated by normal-phase SPE, followed by a single analysis using multidimensional gas chromatography-time of flight mass spectrometry (MDGC-TOFMS), which is similar to the recently popularized technique of GCÂGC. This two-column sequential analysis followed by TOFMS identifications is able to accurately identify more of the polar components of jet fuel. Automated data analysis routines, based on improved mass spectral library identifications (due to the better chromatographic separations), are able to determine individual components in the polar fractions that are of interest. Spreadsheet-based sorting of the highest quality identifications was also performed and used to quantify important polar fuel classes such as amines, indoles, pyridines, anilines, sulfur compounds, oxygenates, aromatics, and others. The relative amounts of each group were determined and related to similar measurements found in the literature. The ability to identify and quantify polar components in fuel may be useful in developing relationships between fuel composition and properties such as thermal stability.

No abstract

No abstract