库仑滴定法测定土壤及水系沉积物中硫含量

Determination of Total Sulfur in Soil and Stream Sediments by Coulometric Titration

为提高土壤及水系沉积物中全硫含量测定结果准确度,提出了库仑滴定法进行全硫量测定的方法优化,探究了称样量、炉温、载气流量和催化剂种类等不同因素影响对土壤及用水系沉积物中硫含量的测定准确度的影响。测试结果表明:库仑滴定法测定土壤及水系沉积物中硫含量的最佳工作条件为炉温1200℃,称样量0.1000 g,载气流量1.0 L/min;纯铁催化剂对于极高或极低硫值样品的测定结果稳定度更高,WO3催化剂具有更高的性价比;库仑滴定法相较于燃烧-碘量法和高频红外法对低硫含量样品测定更准确。相较于燃烧-碘量法和高频红外法,库仑滴定法对低硫含量样品测定更准确。

In order to improve the accuracy of the measurement results of sulfur in soil and stream sediment,the optimization of determination of total sulfur content by coulometric titration was proposed.Different factors such as the sample quantity,temperature,gas flow rate and catalyst on accuracy of the determination of total sulfur content in soil and stream sediments were explored.The experimental result shows that the optimum working conditions for coulometric titration method are 1200℃ furnace temperature,0.1000 g weighing volume and 1.0 L/min carrier gas flow rate.The determination result of pure iron catalysts has more stable for samples with extremely high or extremely low total sulfur,but tungsten trioxide is more cost-effective.Compared with combustion iodometry and high frequency combustion infrared absorption method,this method is more accurate for the determination of low sulfur samples.