SEATTLE, WASHINGTON—To measure for the presence of oil in seafood, NOAA's scientists in the gulf region use a team of 10 "expert sniffers" trained to detect the distinctive smell. The same samples are sent to scientists here at the Northwest Fisheries Science Center who prepare them for chemical analysis for polycyclic aromatic hydrocarbons (PAHs) using a 3-day cleaning, drying, and preparatory step. NOAA research chemist Daryle Boyd showed ScienceInsider frozen samples of red snapper and shrimp kept in glass jars in a freezer.
To ensure accurate results, the samples are marked "just with numbers and species" so the scientists analyzing them don't know where they came from or the results of the sniff test, explained Boyd. She worked alone late in the afternoon Wednesday to insert about a dozen samples in metal test tubes into a machine called a solvent extractor. ("Most people here are early birds, coming in 5, 6 a.m.," said Boyd, who wore Crocs, jean shorts, and latex gloves as she worked.)