The experiment using various sampling weights also validated that the analytical curves were linear from the detection limit to the highest standard. To verify the accuracy of this paper's results, analyses of these two samples were repeated with special attention given to proper drying of the samples before analysis. Table 2 shows the results for the replicate analyses of these coals, the repeats, and Vorres' published data. Argonne went to great lengths to seal these coals in an oxygen-free environment. Because analysis in the U.S. Geological Survey laboratories was not done immediately after the ampoules were opened, it is likely that the subbituminous coal and the lignite oxidized.
Bituminous coals are characteristically more stable.
The precision of this method is within the 0.1 percent relative standard deviation, which is well within the accepted deviation for this type of analysis. The analysis of NIST 1635 indicates that the accuracy is also excellent. Created and maintained by the EERT WWW Staff .