Rapid, easy multielement analysis of whole coal via slurry-injection atomic absorption spectrophotometry. [23 elements; absorption spectroscopy]

In recent years, a few laboratories have reported on the use of flame atomic absorption/emission methods for the analysis of solids directly, bypassing normal ashing and dissolution steps. We have developed an atomic absorption method for the direct analysis of whole coal by injection of powdered coal slurries into either flames or graphite furnaces. This paper greatly expands the preliminary observations of O'Reilly on the slurry-injection approach to flame AA analysis of coal. Our work is oriented toward a comprehensive exploration of the capabilities of this general approach for determining a wide variety of elements in some difficult-to-digest solid matrices such as coal, coal ash, oil shale, limestone, pigments, glasses, and selected ores. That is, solid matrices with relatively constant major component compositions. Most of our work has concerned flame atomization AA procedures, which are generally faster and more convenient than non-flame electrothermal atomization techniques. Ease of sample preparation plus greatly increased speed of analysis using a commonly available instrument are in the main advantages of this slurry injection AA method for coal analysis. Accuracies are certainly good enough for geochemical explorations, and are actually in the range of values reported for conventional AA determinations.