土壤全硫提取和测定方法的改进

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。

Improvement of Extraction and Determination Method of Total Sulfur in Soil

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 BaSO4 turbidity method were developed.Result] The soil digestion solution was digested to 1-2 mL in the process of extracting the sulfur from soil by the method of nitric acid perchloric acid,and then were determined with the improved BaSO4 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.