Determination of Sulfur in Soil by Inductively Coupled Plasma-Optical Emission Spectrometry with Four Acids Open Dissolution

At present, sulfur in soil is mainly determined by X-ray Fluorescence Spectrometry and tube furnace combustion iodine methods. The analysis speed of these two methods is slow, and the analysis accuracy is poor for both high and low content samples, difficult to meet the requirements of accurate and rapid determination of many samples. In order to improve the speed and accuracy of analysis, a new method for the determination of sulfur in soil samples by Inductively Coupled Plasma-Optical Emission Spectrometry combined with four acids digestion was developed. In this paper the digestion effect of aqua regia, aqua hot water bath and HCl-HNO₃-HF-HClO₄ is compared. The four acids digestion method was proven to better dissolve sulfur in soil samples. The method is simple, rapid and accurate with a low detection limit of 10 μg/g, analysis range between 33.3 μg/g and 50000 μg/g, and relative standard deviation between 0.47% and 4.05%. Many elements such as potassium, sodium, calcium, magnesium, iron, manganese, beryllium, lithium, lanthanum, cerium, scandium, vanadium, cobalt, nickel, and titanium can be determined simultaneously in a solution without increasing analysis cost. The method, which has been verified with actual samples, is suitable for application in the geological industry.