Preparation of Five China Sea and Continental Shelf Sediment Reference Materials with Ultra Fine Particle Size
The preparation and certification of five China Sea and continental shelf sediment reference materials MSCS-1 -5 are reported. The raw samples were collected separately from the East China Sea and the South China Sea. First,they were ground by a ball mill to a homogenous powder of less than 74 μm,then these samples was further processed by an ultra-fine processing technique,a jet mill,to form an ultra-fine powder. The particle size distribution of the samples was determined with a laser particle-analyser,their average particle size is 4 μm. The homogeneity was tested by high-precision WD-XRF and the minimum sampling mass is 5 mg,which was confirmed by XRF,ICP-AES and ICP-MS. Twelve laboratories participated in the cooperative study and 60 constituents were determined. 50 and 51 components were certified as certified values and 1 and 2 components as reference values respectively for MSCS-1 and MSCS-2,52 constituents were certified as certified values for MSCS-3,4 and 5. The sum of the major and minor components in the five reference mate-rials MSCS-1 -5 is 99. 9% ,99. 6% ,100. 4% ,100. 1% and 99. 7% ,respectively.