Determination of lead in carbonate rocks by carbon-furnace atomic-absorption spectrometry after dissolution in nitric acid.
A simple and rapid method for the determination of 1-100 ppm of lead in carbonate rocks is described. Dissolution of the rock samples in 10% v v nitric acid is shown to give precise and accurate results even though silicates in the samples remain undissolved. A more time-consuming but complete dissolution of the sample with hydrofluoric acid may be used if preferred. The increase in sensitivity and freedom from matrix interference obtained by the use of a carbon-furnace atomizer eliminate the necessity for preconcentration of the lead, saving time and preventing errors from contamination or losses derived from inefficient extraction procedures. The detection limit and precision of the method are 0.4 ppm and 6% (relative standard deviation at the 3-ppm lead level) respectively and accurate results were obtained for the analysis of standard rock samples.
Campbell
W C
WC
Department of Pure and Applied Chemistry, University of Strathclyde, Cathedral Street, Glasgow G1 1XL, Scotland.
Ottaway
J M
JM