A visual comparison method for semiquantitative spectrographic analysis of plant ash by dc arc technique has been applied to a wide variety of plant material. A split slit technique utilizing a Hartmann diaphragm and step filter assemblage enables the simultaneous recording of volatile
elements from a short burn at 100% transmission and less volatile elements from a total energy burn at 15% transmission from the same electrode charge. Volatile elements, e.g., Ag, As, Bi, etc., are thus detected at low concentrations without the necessity of a separate analysis. Standards
in a plant ash base are prepared in progressively lower concentrations from spectrographically pure powders in ranges applicable to most plants. Results are reported as six possible logarithmically spaced intervals per order of magnitude. Results show the repeatability to be within one reporting
interval of the standards at the 68% confidence level and within two reporting intervals of the standards at the 95% confidence level. The over-all speed of the method suggests an application to large numbers of samples, and the analysis of more than 800 samples per man-month attests to the
value of this method in reconnaissance studies.
United States Geological Survey, Denver, Colorado 80225
Publication date: November 1, 1972
More about this publication?
The Society publishes the internationally recognized, peer reviewed journal, Applied Spectroscopy, which is available both in print and online. Subscriptions are included with membership or can be purchased by institutional or corporate organizations. Abstracts may be viewed free of charge. Previously published as Bulletin (Society for Applied Spectroscopy)