Solid-phase microextraction (SPME) was applied, in conjunction with gas chromatography-mass spectrometry, to the analysis of volatile organic compounds (VOCs) in human breath samples without requiring exhaled breath condensate collection. A new procedure, exhaled breath vapor (EBV) collection, involving the active sampling and preconcentration of a breath sample with a SPME fiber fitted inside a modified commercial breath-collection device, the RTube, is described. Immediately after sample collection, compounds are desorbed from the SPME fiber at 250 degrees C in the GC-MS injector. Experiments were performed using EBV collected at -80 degrees C and at room temperature, and the results compared to the traditional method of collecting exhaled breath condensate at -80 degrees C followed by passive SPME sampling of the collected condensate. Methods are compared in terms of portability, ease-of-use, speed of analysis, and detection limits. The need for a clean air supply for the study subjects is demonstrated using several localized sources of VOC contaminants including nail polish, lemonade, and gasoline. Various simple methods to supply clean inhaled air to a subject are presented. Chemical exposures are used to demonstrate the importance of providing cleaned air (organic vapor respirator) or an external air source (tubing stretched to a separate room). These techniques allow for facile data interpretation by minimizing background contaminants. It is demonstrated herein that this active SPME breath-sampling device provides advantages in the forms of faster sample collection and data analysis, apparatus portability and avoidance of power or cooling requirements, and performance for sample collection in a contaminated environment.

Actual or surrogate chemical, biological, radiological, nuclear, and explosive materials and illicit drug precursors can be rapidly detected and identified when in aerosol form by a Single-Particle Aerosol Mass Spectrometry (SPAMS) system. This entails not only the sampling of such particles but also the physical analysis and subsequent data analysis leading to a highly reliable alarm state. SPAMS hardware is briefly reviewed. SPAMS software algorithms are discussed in greater detail. A laboratory experiment involving actual threat and surrogate releases mixed with ambient background aerosols demonstrates broad-spectrum detection within seconds. Data from a field test at the San Francisco International Airport demonstrate extended field operation with an ultralow false alarm rate. Together these data sets demonstrate a significant and important advance in rapid aerosol threat detection.Single-Particle Aerosol Mass Spectrometry (SPAMS) was initially developed at Lawrence Livermore National Laboratory to detect and identify biological aerosols.1,2 Since such aerosols are arguably among the most difficult to rapidly and accurately detect, this was a significant achievement. It also had immediate and important applications: biological warfare agents are potentially lethal in picogram quantities, 3,4 have been aerosolized for terrorist purposes, 5,6 and must be rapidly detected if medical treatment is to be maximally effective. Nonetheless, there are many other types of particles that are lethal or indicative of nefarious activity and far more frequently encountered. Chemical, biological, radiological, nuclear, and explosive (CBRNE) materials and illicit drugs or their precursors can all form airborne particles. Consequently, SPAMS is now being investigated as a potential means for their detection. SPAMS is even being explored as a means to analyze human respiratory effluent for various biomedical applications. 7,8 Such applications, however, present unique challenges and will not be discussed here. It should be noted that the technique was initially called Bio-Aerosol Mass Spectrometry (BAMS), but due to its growing range of applications a name change was requisite.In brief, SPAMS samples particles directly from the air and then reagentlessly and individually analyzes them. Correlated data on single-particle size, charge, and laser-induced fluorescence (LIF; measured for two excitation wavelengths independently) can be collected in addition to a full dual-polarity mass spectrum. Accurate single-particle identification is possible, and very accurate alarms can be triggered. Early SPAMS hardware evolved from ATOFMS instruments, 9 which were developed by the Prather group at U.C. Riverside and commercialized by TSI Inc., but the newest SPAMS systems are entirely distinct. Other varieties of aerosol mass spectrometer exist as well, 10,11 but few if any such instruments were specifically intended for rapid detection of lowconcentration aerosols in high-concentration backgrounds. The instrument of Wuijckhuijse et al....

The application of single-particle aerosol mass spectrometry (SPAMS) to the real-time detection of micrometersized single particles of high explosives is described. Dualpolarity time-of-flight mass spectra from 1000 single particles each of 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazinane (RDX), and pentaerythritol tetranitrate (PETN), as well as those of complex explosives, Composition B, Semtex 1A, and Semtex 1H, were obtained over a range of desorption/ionization laser fluences between 0.50 and 8.01 nJ/µm 2 . Mass spectral variability with laser fluence for each explosive is discussed. The ability of the SPAMS system to identify explosive components in a single complex explosive particle (∼1 pg) without the need for consumables is demonstrated.