Assessing tritium contamination on three surfaces

The performance of the wipe test using filter papers or cotton swabs was examined in order to determine recoveries of contamination on selected surfaces by low energy, β emitting radioisotopes. Filter papers or cotton swabs were saturated with Scintiverse BD, Ultima Gold, Contrad 70, dish soap, methanol, ethyl acetate, or maintained dry. Wipes were taken from Formica, stainless steel or polyurethane treated wood surfaces which were previously treated with [3H]triolein or [3H]thymidine. There were significant differences between recoveries by dry and saturated wipes. The dry wipes had poor overall recoveries which were less than 8% from any surface using either filter papers or cotton swabs. Saturated wipes had recoveries up to 50% but were significantly influenced by the saturating solution and the chemical form of the radioisotope. Cotton swabs yielded similar results when compared to filter papers for recoveries of both compounds from the three surfaces. Surface type had a significant influence on the recoveries of both compounds during the wipe test.