Application of a High Surface Area Solid-Phase Microextraction Air Sampling Device: Collection and Analysis of Chemical Warfare Agent Surrogate and Degradation Compounds

Abstract

This work examines a recently improved, dynamic air sampling technique, high surface area solid-phase microextraction (HSA-SPME), developed for time-critical, high-volume sampling and analysis scenarios. The previously reported HSA-SPME sampling device, which provides 10-fold greater surface area compared to commercially available SPME fibers, allowed for an increased analyte uptake per unit time relative to exhaustive sampling through a standard sorbent tube. This sampling device has been improved with the addition of a type-K thermocouple and a custom heater control circuit for direct heating, providing precise (relative standard deviation ∼1%) temperature control of the desorption process for trapped analytes. Power requirements for the HSA-SPME desorption process were 30-fold lower than those for conventional sorbent-bed-based desorption devices, an important quality for a device that could be used for field analysis. Comparisons of the HSA-SPME device when using fixed sampling times for the chemical warfare agent (CWA) surrogate compound, diisopropyl methylphosphonate (DIMP), demonstrated that the HSA-SPME device yielded a greater chromatographic response (up to 50%) relative to a sorbent-bed method. Another HSA-SPME air sampling approach, in which two devices are joined in tandem, was also evaluated for very rapid, low-level, and representative analysis when using discrete sampling times for the compounds of interest. The results indicated that subparts per billion by volume concentration levels of DIMP were detectable with short sampling times (∼15 s). Finally, the tandem HSA-SPME device was employed for the headspace sampling of a CWA degradation compound, 2-(diisopropylaminoethyl) ethyl sulfide, present on cloth material, which demonstrated the capability to detect trace amounts of a CWA degradation product that is estimated to be less volatile than sarin. The rapid and highly sensitive detection features of this device may be beneficial in decision making for law enforcement, military, and civilian emergency organizations and responders, providing critical information in a contaminated environment scenario when time is of the essence.

Capillary microextraction: A new method for sampling methamphetamine vapour

“…Several groups have been investigating the use of high surface area SPME devices [30][31][32][33], in order to increase the sensitivity and selectivity of the sampling prior to instrumental analysis. We considered the use of such devices as a complementary method to wipe sampling for determining the extent of methamphetamine contamination at a former clandestine laboratory site.…”

Fieldable Mass Spectrometry for Forensic Science, Homeland Security, and Defense Applications

“…When the sampler is returned to the laboratory, chemists can thermally desorb the VOCs directly into the injection port of a commercial benchtop GC-MS and obtain quantitative data (Ramsey et al, 2009). An improved version of this prototype was used for trace level detection of surrogates of a CWA and its degradation products (Stevens et al, 2013).…”

Method for Derivatization and Detection of Chemical Weapons Convention Related Sulfur Chlorides via Electrophilic Addition with 3-Hexyne

“…The convention related chemicals (CRCs) are annexed in the CWC text as Schedule 1–3 chemicals. , The CRCs are categorized in three schedules on the basis of their potential use as CWAs or their precursors. Even though the threat by chemical weapons has been reduced by the implementation of the CWC, their use in conflict and in acts of terrorism is still reported. − Therefore, the advancement in analytical capabilities of CRCs still is an active area of current research. − …”