Abstract
This chapter describes laboratory methods to conduct chemical characterization of solids, liquids, and gases related to geoenvironmental practice. The analysis of solids extends to testing techniques that determine mineralogical composition, such as diffraction, thermogravimetric analyses, and spectroscopy, as these are highly relevant to engineering practice. Analysis of the chemical composition of solids in geoenvironmental practice is performed through a two-step process: digestion of the solid into the liquid phase followed by analysis of the resulting digestion solution. Liquid samples including aqueous and digestion solutions can be characterized by utilizing wet chemistry methods for testing general parameters, metals and metalloids, organics, and other compounds. Analysis of gases in geoenvironmental practice is mostly required for in situ or on-site applications such as volatile organic compound detection in contaminated sites and gas analysis in landfill collection systems including methane emissions. ATDSR provides a comprehensive guide on different requirements and testing methods for landfill gas.