Abstract:
BACKGROUNDIn the multi-target regional geochemi-cal survey project, sulfur is one of the analyzed elements. During measurement of samples with a high-frequency infrared carbon-sulfur analyzer, different factors include the blank of the crucible, water vapor in the pipeline, different sample weights, sample and flux stacking order, and different flux additions, which would result in poor reproducibility of sulfur and even a negative value.
OBJECTIVESTo eliminate factors that affect the repeatability of sulfur analysis and improve the accuracy of sulfur analysis.
METHODSThe conditions for determination of sulfur in soil-stream sediments were optimized by comparing the sample weight, sample and flux stacking order, and flux amount.
RESULTSIn the case of reducing the blank value of the crucible and strictly controlling the humidity in the trachea of the instrument, the calibration curve shows a good relationship (r ≥ 0.9990) after the sample was analyzed by mixing 0.08g sample, 0.5g iron and 1.0g tungsten. After analyzing the different results using a calibration curve of the appropriate concentration, the logarithmic differences of the sulfur analysis results are -0.036-0.062 and the relative standard deviations (RSDs) are 7.13%-9.93%.
CONCLUSIONSBoth the logarithmic difference and the standard deviation meet the requirement of multi-target regional geochemical survey (1:2500000), indicating that the analytical results of this method are accurate and reproducible.
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