【国外标准】 Standard Practice for Acid-Extraction of Elements from Sediments Using Closed Vessel Microwave Heating

4.1 Partial extraction of soils and sediments can provide information on the availability of elements to leeching, water quality changes, or other site conditions.4.2 Rapid heating, in combination with temperatures in excess of the atmospheric boiling point of nitric acid, reduces sample preparation or reaction times.4.3 Little or no acids are lost to boiling or evaporation in the closed digestion vessel so additional portions of acid may not be required. Increased blank corrections from trace impurities in acid are minimized.1.1 This practice covers the digestion of soils and sediments for subsequent determination of acid-extractable concentrations of certain elements by such techniques as atomic absorption and atomic emission spectroscopy.1.1.1 Concentrations of arsenic, cadmium, copper, lead, magnesium, manganese, nickel, and zinc can be extracted from the preceding materials. Other elements may be determined using this practice.1.2 The analytical sample is arbitrarily defined as that which passes a 10-mesh (approximately 2 mm openings) screen and is prepared according to Practice D3974.1.3 Actual element quantitation can be accomplished by following the various test methods under other appropriate ASTM standards for element(s) of interest.1.4 The detection limit and linear concentration range for each element is dependent on the atomic absorption or emission spectrophotometric technique employed and may be found in the manual accompanying the instrument used.1.5 Before selecting a digestion technique, the user should consult the appropriate quantitation standard(s) for any special analytical considerations, and Practice D3974 for any special preparatory considerations.1.6 The extent of extraction of elements from soils and sediments by this method is dependent upon the physical and mineralogic characteristics of the prepared sample.1.7 The values stated in both inch-pound and SI units are to be regarded separately as the standard. The values given in parentheses are for information purposes only.1.8 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. For specific hazard statements, see Section 8.1.9 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.