土壤全硫提取和测定方法的改进

Improvement of Extraction and Determination Method of Total Sulfur in Soil

[目的]研究大批量测定土壤样品硫含量的简单、经济、有效的方法。[方法]对氧化法提取全硫和BaSO_4比浊法进行完善。[结果]将土壤消解液消解剩余至1~2 m L,适量消解提取液(校准曲线加入等量空白消解液),加入(1+2)甘油-乙醇稳定剂、冰醋酸缓冲剂,以硝酸钡作为沉淀剂,电磁搅拌1 min,静置20 min后,40 min内在波长440 nm处测定比浊液吸光度,得到精确的试验结果。[结论]该方法可应用于高硫土壤样品中全硫的测定。

[Objective] To study a simple,economic and effective method to measure the sulfur content in soil samples.[Method] Total sulfur extraction process by oxidation method and BaSO_4 turbidity method were developed.[Result]The soil digestion solution was digested to 1-2 m L in the process of extracting the sulfur from soil by the method of nitric acid perchloric acid,and then were determined with the improved BaSO_4 turbidity. A proper amount of digestion solution（ calibration curve was added to the same amount of blank solution）,（ 1 ＋ 2） glycerol-ethanol was used as stabilizer,using acetic acid solution to ease the change of the acidity of solution,adding 5% barium nitrate solution as precipitating agent instead of barium chloride solution,electromagnetic stirring for 1 min,and then at the intrinsic wavelength of 440 nm,total sulfur in the soil was determined after 20 minutes and within 40 minutes,then right result was gotten.[Conclusion]The method can be applied to the determination of total sulfur in samples of high-sulfur soil.