Preparation of Yangtze River Delta Sediment Reference Materials

More than 10 harbour and estuarine sediment reference materials have been developed in the United States, Canada and other countries, but most of them focus on organic pollutants and radionuclide, and lack certified values. Three sediment reference materials of the Yellow river delta have been prepared in China in 2007. In order to meet the needs of offshore marine sediment geochemical surveys and resource exploration, two sediment standard materials of the Yangtze river delta were prepared according to ISO guidelines and technical standards for reference standards at the national level. Two samples were collected according to different particle sizes, and were dried and ball milled to 200 mesh. Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) were used to test the homogeneity. Results show that the F values for the variance test were less than the threshold, which indicates good homogeneity. X-ray Fluorescence Spectroscopy was used for a four-time stability test in two years. No statistically significant changes were observed and the stability of the samples was good. A total of 13 accurate and reliable analytical methods were used in 12 technologically significant laboratories to finalize the contents of 53 elements. The major elements show gradient distribution with 16.42% and 11.48% of Al₂O₃. These two reference materials have multiple elements with determined values by accurate and reliable methods, which can provide quality assurance for the analysis and testing during geological and environmental surveys in the Delta region.