Yankuang ceshi (Jul 2022)
Determination of Sulfur in Different Types of Geochemical Samples by ICP-OES with Acid Dissolution and Combustion-Infrared Absorption Spectrometry
Abstract
BACKGROUND Inductively coupled plasma-optical emission spectrometry (ICP-OES) and combustion-infrared absorption spectrometry are the most widely used methods to measure sulfur content in geological samples. The ICP-OES method has high sensitivity and good stability, but it is greatly affected by sample pretreatment and matrix interference. Combustion-infrared absorption spectrometry is convenient and efficient, but due to the interference of crystal water infrared absorption, the analysis of samples with low sulfur content has poor stability. OBJECTIVES To study the application scope of the two methods in geological sample analysis. METHODS The sulfur content of samples was determined by ICP-OES and combustion-infrared absorption spectrometry. The detection limit, detection range, precision, accuracy and analysis efficiency of the two methods was compared in order to study and understand the performance of the two methods in sulfur measurement of geological samples. RESULTS The best test condition of combustion-infrared absorption spectrometry was determined thus: optimal sample weight of 0.0500g, combustion time of 25s, analysis time of 40s and oxygen analysis flow rate of 4.0L/min. The detection limit of combustion-infrared absorption spectrometry was 10×10-6 and the detection range was 10×10-6-470000×10-6. The accuracy relative standard deviation (RSD) of the method was less than 6% (n=12) and the absolute value of relative error was less than 8%. CONCLUSIONS For the analysis of low-sulfur samples, ICP-OES method can be used to analyze or compare, and multi-element simultaneous measurement can be determined. Batch samples or samples with a complex matrix can be analyzed by combustion-infrared absorption spectrometry, which is more convenient and efficient.
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