A knowledge of the inorganic constituent composition in a waste is often required for the selection of appropriate waste disposal practices. Solid waste may exist in a variety of forms and contain a range of organic and inorganic constituents. This practice describes a drying and ashing step that may be applied to remove moisture and volatile and nonvolatile organic constituents prior to determining nonvolatile metals. Generation of a dry ash concentrates the inorganic constituents of interest and makes the LiBO₂ fusion feasible for a greater variety of waste samples. Acidification of the LiBO₂ fusion mix results in a solution amenable to inductively coupled plasma (ICP) or atomic absorption spectrometry (AAS) analysis.

1.1 This practice covers the drying, ashing, and solubilization of solid waste using a lithium metaborate (LiBO₂) fusion for the subsequent determination of inorganic constituents by argon plasma emission spectroscopy or atomic absorption spectroscopy.

1.2 The following elements may be solubilized by this practice:

1.3 This practice has been used successfully with a bauxite ore and a neutralized metal treatment sludge. The practice may be applicable to other elements not listed above. Some metals, such as cadmium and zinc, may volatilize from some samples during the drying, ashing, or fusion steps. The analyst is responsible for determining whether the practice is applicable to the solid waste being tested.

1.4 This practice is intended for the solubilization of nonvolatile inorganic constituents in solid waste. The LiBO2 fusion is appropriate for a silicate matrix or acid resistant samples.

1.5 This standard does not purport to address all of 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 determine the applicability of regulatory limitations prior to use. For specific hazard statements see Section 7.