Determination of Total Sulfur in Fifteen Geological Materials Using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) and Combustion/Infrared Spectrometry

A method for the determination of total sulfur in geological materials by inductively coupled plasma-optical emission spectrometry (ICP-OES) is described. We show that good results were obtained using this method even for sample types with very low (< 20 mu g g(-1)) sulfur concentration (e.g., peridotite). Sulfur was determined in fifteen geological reference materials with different sulfur contents. For reference materials with certified sulfur contents, the ICP-OES method gave results in excellent agreement with certified values, and uncertainties better than 4% RSD. ICP-OES results for sulfur in other reference materials yielded RSDs better than 10%, where S concentrations were > 100 mu g g(-1) (except for diabase W-2a, 16% RSD). Reference materials with lower sulfur contents (< 40 mu g g(-1)) showed much higher RSDs (17-18%). Except for RMs with certified values for sulfur, most data obtained by the combustion infrared detection method generally showed higher concentrations than those measured by ICP-OES and a better RSD (<= 8% for all materials except DTS-2b).