Strippable coatings for forensic collection of trace chemicals from surfaces

Surface sampling for chemical analysis plays a vital role in applications like environmental monitoring, industrial hygiene, homeland security, and forensics. The standard surface sampling tool is a simple cotton gauze pad, but as techniques become more sensitive and the variety of analytes increases, gauze is failing to meet the needs of the community. Here, the collection of eight small molecules from glass surfaces with three different commercial spray-on, strippable coatings was demonstrated and their collection efficiency, as measured by gas chromatography/mass spectrometry, was compared to that of a standard cotton gauze. The three coating systems recovered 87-95% of the each compound, on average, from a nominal initial surface coverage of 0.1 g/m(2) per analyte. These recoveries were 3-fold better than the cotton gauze which had an average collection efficiency of 31%.