Oyster Tissue This Standard Reference Material (SRM) is intended primarily for use in evaluating analytical methods and instruments used for the determination of the mass fraction values of selected elements and proximates in marine bivalve tissue, foods, or similar materials. Source and Preparation of Material: The oysters (Crassostrea virginica, an American Eastern oyster) used for the preparation of SRM 1566b were purchased from Bon Secour Fisheries, Inc., Bon Secour, AL. The oysters were collected from the Gulf of Mexico, shucked, rinsed twice to remove sediment and shells, packed and sealed in polyethylene bags, and frozen. The frozen oysters and fluids were shipped in styrofoam coolers containing dry ice to NIST. At NIST, the oysters and fluids were ground in a Robot-Coupe Vertical Cutter Mixer that was equipped with a stainless steel bowl and titanium blades. The oyster tissue was blended for 100 s into a slurry; approximately 5 kg of slurry was poured into each of 40 specially cleaned aluminum trays outfitted with temperature probes, and frozen at –20 °C. The trays were taken to a large freeze-drying facility at the Frederick Cancer Research and Development Center, Natural Products Group in Frederick, MD. The freeze-dryer’s initial temperature was –45 °C and gradually increased to a temperature of 10 °C over a period of five days. The freeze-dried material was stored at –20 °C, then broken into smaller pieces, blended in the Robot-Coupe Mixer, jet milled, and homogenized in a V-blender for 30 min to 40 min. The material was radiation sterilized (60Co) at Neutron Products, Inc., Dickerson, MD, for approximately 5 h to an absorbed dose of 30 kGy and then aliquoted into amber bottles.
keywords: biological material , animal tissue , Fish/Shellfish , foodstuff , trace elements , heavy metals , nutrients , organometallics , Mercury speciation, speciation analysis |