The Determination of Mercury in Small Terrestrial and Nonterrestrial Rock Samples by Atomic-Absorption Spectroscopy, and the Study of Mercury Release at Elevated Temperatures

Abstract

An atomic-absorption method was developed for determining subnanogram amounts of mercury in 100 mg of samples and for studying the release of mercury at elevated temperatures. The rock samples were contained in a sidearm of a quartz cell, and the mercury released by heating was determined by measuring the absorption of 2537-Å light passed through the cell. For a number of terrestrial and nonterrestrial samples analyzed, the results obtained agreed within a factor of 2 with neutron activation methods. This agreement is considered satisfactory since samples are not homogeneous. For a lunar sample that contained 1.79 ppb of mercury, the precision expressed as standard error is ±0.05 ppb. The sensitivity of this method for 1% light absorption is 0.03 ng; the limit of detectability is of the order of 0.01 ng. Mercury-release patterns obtained by atomic absorption methods also were in reasonable agreement with mercury-release patterns obtained by neutron-activation methods.