1.1 This practice establishes uniform procedures to develop, select, collect, prepare, and use oxidized, relatively unpolluted, aquatic natural-matrix bed-sediment reference samples for the collaborative testing of chemical methods of analysis for sediments and similar materials. Reference samples prepared using this practice are intended for use as natural sediments, analyzable for major, minor, and trace elements, and general physical/organic analyses only. The samples are not designed or tested for environmental pollutants such as trace organic compounds.

1.2 Few, if any aquatic sediment reference materials have been certified, defined, or are even available for developing or evaluating partial and sequential extraction procedures. This practice describes factors and considerations in site selection, sample characteristics, collection, and subsequent raw sample treatment needed to prepare natural-matrix bed-material sediments for use as partial or sequential extraction procedure reference test samples. The user of this practice is cautioned that in light of the many variables that may affect natural materials, neither the list of factors included for evaluation nor preparation of natural-matrix reference samples should be considered as all inclusive. It is the user's responsibility to ensure the validity and applicability of these practices for preparing specific-matrix samples appropriate for testing the constituents of interest and the operationally defined extraction procedures utilized.

1.3 This standard does not purport to address the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.