Soil Reference Materials Of Elemental Forms In China

Chemical analysis for element forms is the frontier in the field of analyticalchemistry. It plays an important role in the research of environment and ecology. In theindustrial years, the soils have been polluted seriously due to the fertilization, sewageand industry wastes etc. These pollution materials is harmful to man's healthy. Not allmetals are available for biology. Only the bioavailable forms of metals are harmful orhealthful to biology. Thus it is important to study on the forms of metals in the soil.Many papers on elemental forms in soils and sediments have been published sinceTessier gave the five steps' method of sequential extractions for metals forms. Thecurrent problems of metal forms include: (1) Analytical procedures for sequentialextraction of bioavailable metals are not well recognized (2) There are nowell-recognized standard reference samples. These problems lead to incomparable datagiven by the different laboratories.A seven-step sequential chemical extractionprocedure was designed by the Geological Analysis Laboratory of Anhui and confirmedthe China Geological Survey.This paper reviews the current methods used for extraction procedures. The authorgives a preliminary research on Metal Forms Reference Sample of Soil prepared by byIGGE (Institute of Geophysical and Geochemical Exploration), base on the analyticalprocedure designed by the Anhui laboratory.Preliminary results and data on Metal Forms Reference Sample of Soil are given.Through the evaluation of the data, the author found the reproducibility and precisionusing the seven-step sequential extractions are not satisfactory, particularly for the ionicexchangeable forms. The main reasons are due to high blank values and high detectionlimits. It also gives description on the distribution of various metal's forms in thedifferent soils based on this preliminary results.