SOLID SCINTILLATION PROXIMITY MEMBRANES - II - USE IN WIPE TEST ASSAYS FOR RADIOACTIVE CONTAMINATION

Membranes containing the inorganic fluor cerium-activated yttrium sili cate were prepared using three different coagulation techniques and we re subsequently evaluated for their suitability in cocktail-less wipe tests for radioactive (H-3-cortisol) contamination. Wipe tests employi ng fluor-containing membranes that were prepared by direct vitrificati on were nearly as efficient as the conventional wipe test assays that require the use of scintillation cocktails at detecting radioactive co ntamination on the surfaces. The sensitivity of detecting radioactivit y on the contaminated surfaces was significantly greater when the side of the membrane exposed to air during coagulation was used in the wip e tests compared to the side of the membrane exposed to the glass. Tre atment of the membranes with DMF induced a change in surface morpholog y which allowed more radioactivity to be transferred from the surface, but also caused the leaching of the fluor from the membrane. This res ulted in an overall decrease in detection efficiency. (C) 1998 Elsevie r Science B.V. All rights reserved.