Surface Wipe Sampling
The Surface Wipe Sampling Toolkit
The surface wiping procedure followed the methods previously published by our group. All wipe sampling supplies, along with written instructions, are provided in a standardized toolkit and delivered prior to sampling dates. The supplied 10 cm x 10 cm plastic template is to be placed on the selected surfaces to demarcate the area for sampling. Irregular surfaces like doorknobs can be measured using the supplied flexible ruler for surface area calculations. The area within the template is sampled for contamination by wiping vertically and then horizontally, folding the prior to switching directions filter. A video demonstration of the wipe sampling method can be seen below.
Laboratory analysis to assess contamination consisted of each wipe sample being desorbed, spiked with isotopically labeled internal standard, and centrifuged. One milliliter of the clear solution was placed in an autosampler vial and analyzed with an LC-MS/MS system consisting of an Agilent 1200 series high-performance liquid chromatography system (G1312B binary pump, a G1379B degasser, and a G1367D refrigerated autosampler) and an Agilent 6410 triple quadrupole mass spectrometer. The mass spectrometer was operated in multiple reaction monitoring mode and utilized positive electrospray ionization.). At least three field blanks samples were analyzed for each set of samples, and a full duplicate set of extracted samples was stored in a freezer for future analysis or checking of results.