Chapter 2 - Analytical methods for elements in coal

Abstract

To precisely determine the relative amount and modes of occurrence of elements in coal, sampling is the first critical step, and it is extremely important to collect the samples tested truly representing the mass of the coal from which they were taken in the field. This chapter introduce the sample methods, i.e., in-situ sampling of coal seams (from a coal face and by drilling) and bulk sampling methods (manual or mechanical sampling). This is followed by preparation of coal samples for analysis. This chapter describes the commonly used analytical techniques for element concentrations, including XRF, ICP-MS, ICP-OES, INAA, AAS, AFS, and ISE. There are two classes of analytical methods for determining the modes of occurrence of elements in coal, i.e., indirect and direct methods, the former including statistical analyses, float/sink methods, and selective leaching techniques and the latter including optical microscopy, PIXE, TOF-SIMS, TEM, SEM-EDS, EMPA, XPS, LA-ICP-MS, XANES, and SRIXE.