Paper | New paper uses Markes’ TT24-7 to detect chemical agents
Wednesday, 20 February 2013 at 4:13:PM
Near real time detection of hazardous airborne substances
J. Leppert et al., Talanta, 2012, 101: 440–446
In this paper, researchers led by Jan Leppert at the University of Bonn in Germany use Markes’ TT24-7 two-trap thermal desorber alongside TOF MS and software from its ALMSCO division to detect chemical warfare agents (CWAs) in air.
The exposure limits of many hazardous compounds are subject to downward revision as their biological effects become better understood, but none come close to the limits specified for CWAs, which can be as low as 10 ppt. This application therefore demands highly senstitive instrumentation, with the added requirement for a short cycle time to ensure rapid response to changing concentrations.
To address these challenges, Leppert’s group used TT24-7 – Markes’ TD system for continuous monitoring – to determine the limits of detection for five CWA simulants. The two-trap technology in TT24-7 gave detection limits in the range 1–11 ppt, at the same time as allowing 100% data capture, even for the most challenging of analytes. In addition, they were able to detect trace concentrations of real CWAs, including sarin, sulfur mustard in diesel, lewisite under humid conditions, and VX. The researchers also used Markes’ glass sorbent tubes and the Calibration Solution Loading Rig (CSLR) to verify calibration measurements.
To ensure a fast cycle time while maintaining sensitivity, the researchers used fast chromatography in conjunction with BenchTOF-dx, ALMSCO’s time-of-flight mass spectrometer. Finally, TargetView compound identification software from ALMSCO was used to process the resulting data.
Leppert says that “the combination of [TT24-7] and the TOF MS results in a very sensitive detection system”. Further developments will focus on using a low-thermal-mass GC, which should allow the system to heat and cool more quickly, thus lowering the cycle time to below 5 minutes.