Rapid analysis of organophosphonate compounds recovered from vinyl floor tile using vacuum extraction coupled with a fast-duty cycle GC/MS

Abstract

In a terrorist event or industrial accident, environmental toxins will be inhomogeneously distributed on surfaces. A field vacuum extractor (FVE) can be used to sample contamination on fixed surfaces in a non-destructive fashion, but application to heterogeneously contaminated environments tends to be limited by the sampling time and time required for analysis, which is ∼15 to 30 min for a laboratory gas chromatograph/mass spectrometer (GC/MS). In the present study, FVE surface sampling was combined with a portable, fast-duty cycle GC/MS that enables analysis of a surface sample approximately every 3 minutes. Employing multiple FVE devices enables rapid measurement of many samples as might be required for characterizing contamination that is inhomogeneously distributed in a release environment. The FVE utilizes solid phase microextraction (SPME) fibers to sorb volatilized compounds from an evacuated headspace enclosed over the surface to be sampled (vinyl floor tile in the present study), over the course of a 30 min sampling time. Recovery of organophosphonate compounds in quantities sufficient to enable identification was achieved sampling floor tile exposed to as little as 30 ng. The amount detected was found to increase in a linear fashion with quantity applied to the floor tile, over three orders of magnitude. Carboxen–polydimethylsiloxane (PDMS) was used as the SPME sorbent phase and was sufficiently robust for multiple sampling and analysis cycles. The carboxen–PDMS retained 2–5% of the organophosphonate compounds after the initial GC/MS analysis, and this fraction could be readily measured in a subsequent re-analysis of the same sample. The re-analysis showed identifiable quantities of the organophosphonate compounds in all experiments except those with the lowest exposure quantities. Thus, once-analyzed carboxen–PDMS fibers may be archived for re-analysis at a later date if desired.