ASTM D4698-21

5.1?The chemical analysis of sediments, collected from such locations as streams, rivers, lakes, and oceans can provide information of environmental significance.

5.2?These practices can be used with either suspended sediment (material actively transported by water) or bed sediment (material temporarily at rest on the bed of a water body).

5.3?Standardized practices for digesting sediments, for subsequent chemical analysis, will facilitate inter- and intra-areal comparisons as well as comparison of data generated by different groups. The use of total digestions also eliminates the ambiguities and interpretational difficulties associated with partial digestions and the operational definitions that accompany them.

1.1?This practice covers two procedures for the total digestion of sediments for subsequent determination of metals by such techniques as flame atomic absorption spectrophotometry, graphite-furnace atomic absorption spectrophotometry, atomic emission spectroscopy, etc.

1.2?This practice is applicable in the subsequent determination of volatile, semivolatile, and nonvolatile metals of sediments.

1.3?Actual metal quantitation can be accomplished by following the various test methods outlined under other appropriate ASTM standards for the metal(s) of interest. Before selecting either of the digestion techniques outlined in this practice, the user should consult the appropriate quantitation standard(s) for any special analytical considerations, and Practice D3976 for any special preparatory considerations.

1.4?The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5?This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.