土壤中易解析硫化物的解析条件研究

Study on Analytical Conditions for Easily Liberating Sulfide in Soil

探索了在以磷酸为酸化剂条件下的实验条件,包括还原剂的添加、酸浓度选择的计算、系统的精密度、准确度的统计,目的是为土壤中硫化物的检出提供借鉴和参考。在以三种土壤为实验样本的实验中,对比磷酸、盐酸、硫酸为酸化剂的检出结果,添加20mL磷酸、1.5g乙二胺四乙酸二钠、0.25g抗坏血酸的检出结果和以硫酸为酸化剂的检出结果比较接近,同样酸度条件下添加抗氧化剂后的检出值和实际样品加标回收率都有提高。三种土壤的相对标准偏差分别是5.6%、6.1%、10.1%,样品加标回收率分别是77.8%、81.9%、64.4%。系统可以完成对部分金属硫化物、易溶硫化物完全解析,且不会因为氧化还原反应造成对S2-的正负误差。

The analytical conditions of addition of reductant and acid concentration for easily liberating sulfide in soil were studied to provide a reference for detection of sulfide in soil.Three soil samples were used for analysis and it was found that addition of SnCl_2 increases the amount of sulfide liberated from soil and recovery rate was also improved by 5%—10%.The precision for three types of soils is 5.6%,6.1%and 10.1%;recovery rate is 77.8%,81.9%,and 64.4%.The results showed that metal sulfides and the soluble sulfide can be liberated and measured accurately under optimal conditions.