| This Certified Reference Material (CRM) is intended for use in the quality assurance of the analysis of organotin and elements. * NIES CRM No.12 Marine Sediment is not available overseas. The starting material for NIES CRM No.12 Marine Sediment was sampled in 1989 at the center of Bay of Tokyo. Approximately 200 kg (wet weight) of surface sediment was sampled by an Eckman-Burge sampler. It was transported to NIES and seawater was removed by filtration. The material was further air-dried for 2 weeks. After removing visible external materials (e.g., shell), it was pulverized in a 7-L high-purity alumina ball-mill to pass 100 μm nylon sieve. The < 100 μm fraction was homogenized in one lot using a V-blender for 3 hrs. Then, 30 g aliquot of the homogenized material was doubly vacuum-packaged into a polyethylene laminate bag with oxygen absorbent to prepare 700 packages. It should be mentioned that NIES CRM No.12 Marine Sediment has not been sterilized to prevent possible decomposition of the organotin compounds by Co irradiation, a standard procedure for sterilization. Instead, they have been vacuum-packaged and stored at -20℃ in a freezer to reduce any bacterial activities. keywords: Environmental material, Particulate matter, Soil/Sediment, Speciation analysis, Tin speciation |
