Carol A. Gent

Determination of chloride in geological samples by ion chromatography

Abstract Samples of silicate rocks are prepared by sodium carbonate fusion and then treated by ion chromatography. The method was tested for geological standards with chloride concentration between 0.003 and 3%. Observed chloride concentrations comparedd favorably with literature values. The relative standard deviation and detection limit for the method were 8% and 7 ppm, respectively. Up to 30 determination per 24-hour period were possible.

The Determination of Fluoride in Geologic Samples by Ion Chromatography

Abstract A method is described for the determination of fluoride in geologic materials utilizing a sodium carbonate fusion and an ion chromatographic method of analysis. Excellent agreement is observed with published values for geologic standards ranging from 0.01% to 6% fluoride in the sample. Estimates of precision were based upon the repetitive analysis of United States Geological Survey standard GSP-1. Results indicate a relative standard deviation for the method of 5%. Detection limits were estimated to be 8 ppm fluoride in the sample at the 90% confidence level.

The Determination of Sulfur and Chlorine in Coals and Oil Shales Using Ion Chromatography

Abstract The determination of sulfur and chlorine in coal and oil shale standards is reported. The procedure utilizes a sample decomposition using Eschkas mixture, followed by an ion chromatographic determination. The method was tested on samples with concentrations ranging from 0.004 to 0.35 percent chlorine and 0.05 to 4.4 percent sulfur. Results compare favorably with values reported in the literature. The detection limits for chlorine and sulfur were 10 and 13 ppm and the precision of the method expressed as a percent relative standard deviation was 6 percent and 5 percent for chlorine and sulfur respectively. Using this method a single operator can prepare and analyze as many as 30 samples per day.