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,

A miniature ion trap mass analyzer is reported. The described analyzer is a 1/5-scale version of a previously reported toroidal radio frequency (rf) ion trap mass analyzer. The toroidal ion trap operates with maximum rf trapping voltages about 1 kV p-p or less; however despite the reduced dimensions, it retains roughly the same ion trapping capacity as conventional 3D quadrupole ion traps. The curved geometry provides for a compact mass analyzer. Unit-mass resolved mass spectra for n-butylbenzene, xenon, and naphthalene are reported and preliminary sensitivity data are shown for naphthalene. The expected linear mass scale with rf amplitude scan is obtained when scanned using a conventional mass-selective instability scan mode combined with resonance ejection. (J Am Soc Mass Spectrom 2006, 17, 916 -922)

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A hybrid mass spectrometer consisting of a magnetic sector, two electric sectors, and a quadrupole mass filter (BEEQ) has been built for the study of polyatomic ion/surface collision phenomena over the energy range of a few electron volts to several keV. Primary ions are generated by electron ionization or by chemical ionization, and the first two sectors are used to deliver a monoenergetic beam of ions, of a selected mass-to-charge m/z ratio, to a decelerator which sets the desired collision energy. The target, which can be introduced into the system without breaking vacuum, is mounted on a goniometer and situated in an electrically shielded region in the center of a large scattering chamber which contains an electric sector and a quadrupole mass analyzer used for kinetic energy and mass measurements on the ejected ions. These analyzers rotate around the scattering center to allow selection of the scattering angle of ions leaving the surface. Ultimate pressures attainable in the main scattering chamber are below 10v9 Torr allowing molecular targets, such as self-assembled monolayers of alkyl thiols on gold, to be examined without surface contamination. Low-energy (20-100 eV) collisions of polyatomic ions are reported, and examples are given of the effects of collision energy and scattering angle on surface induced dissociation mass spectra, The kinetic energy of the inelastically scattered ions is also measured, and in some cases, the internal energy can be estimated, the two measurements together providing information on energy partitioning associated with surface collisions. For example, it is shown that n-butylbenzene molecular ions of 25 eV colliding with ferrocenyl-terminated self-assembled monolayer surfaces, rebound with 10 eV of recoil energy and 3 eV of internal energy. The remainder of the energy goes into the surface. The capability of the BEEQ instrument to provide data on ion/surface reactive collisions is also illustrated with reactions such as alkyl group transfer at self-assembled monolayer surfaces. In addition, data are given showing the ability of the system to provide information on the kinetic energy distributions of ions generated in the course of high-energy collisions at the surface. Mass analysis of the sputtered products provides the instrument with secondary-ion mass spectrometry capabilities.

Collision-induced dissociation (CID) in a quadrupole ion trap mass spectrometer is usually performed by applying a small amplitude excitation voltage at the same secular frequency as the ion of interest. Here we disclose studies examining the use of large amplitude voltage excitations (applied for short periods of time) to cause fragmentation of the ions of interest. This process has been examined using leucine enkephalin as the model compound and the motion of the ions within the ion trap simulated using ITSIM. The resulting fragmentation information obtained is identical with that observed by conventional resonance excitation CID. "Fast excitation" CID deposits (as determined by the intensity ratio of the a 4 /b 4 ion of leucine enkephalin) approximately the same amount of internal energy into an ion as conventional resonance excitation CID where the excitation signal is applied for much longer periods of time. The major difference between the two excitation techniques is the higher rate of excitation (gain in kinetic energy) between successive collisions with helium atoms with "fast excitation" CID as opposed to the conventional resonance excitation CID. With conventional resonance excitation CID ions fragment while the excitation voltage is still being applied whereas for "fast excitation" CID a higher proportion of the ions fragment in the ion cooling time following the excitation pulse. The fragmentation of the (M ϩ 17H) 17ϩ of horse heart myoglobin is also shown to illustrate the application of "fast excitation" CID to [1] by applying to the end-cap electrodes a small supplementary RF voltage, at the same secular frequency as the ion of interest. This produces an increased amplitude of ion motion for ions of that particular mass-to-charge, which then fragment after collisions with the helium buffer gas. This has been the most popular method used for CID in the quadrupole ion trap mass spectrometer and has been used to study an extremely large range of species. Alternative methods for fragmenting ions within a quadrupole ion trap mass spectrometer have been reported and these include surface induced dissociation [2], photo induced dissociation [3,4], boundary activated dissociation [5][6][7], and red shift off resonance large amplitude excitation [8]. All of these methods, to a greater or lesser extent, have sought to improve the ease of performing CID, the amount of fragmentation information obtained, and the mass range of the product ion spectrum. Here we report studies aimed at increasing the speed of performing a single CID experiment. In a conventional resonance excitation CID experiment a small voltage (e.g., 1 Volt peak-peak ) is applied for a set period of time (e.g., 30 ms) followed by a short cooling time prior to analysis. Here we apply a large voltage (e.g., 20 Volts peak-peak ) for a very short period of time (e.g., 90 s) followed by a short cool time prior to analysis.