挥发性硫化物测定法中标准硫化钠溶液的标定

Calibration of Standard Sodium Sulfide Solution in Determination of Volatile Sulfide

目的:探讨挥发性硫化物测定法中标准硫斑制备的影响因素,考察了不同开封时间硫化钠(Na2S·9H2O)的潮解及其硫含量情况对硫斑测定结果的影响。方法:用硫代硫酸钠滴定液对不同开封时间硫化钠配置的标准硫化钠溶液进行标定,确定其中硫含量,并对校正前后标准硫化钠溶液制备的硫斑进行比较。结果:开封时间越长,硫化钠试剂的潮解情况越严重,其硫的含量越低,所得标准硫斑越浅。结论:开封后的硫化钠会缓慢氧化、潮解生成其他含硫化合物并释放出硫化氢气体,使其硫含量降低,在使用硫化钠作为标准物质进行挥发性硫化物测定时,应对硫化钠进行标定,以保证结果的准确性。

Objective:The influence factors of standard sulfur spot preparation in volatile sulfide determination were discussed,The deliquescence of sodium sulfide(Na2S•9H2O)at different opening time and the influence of sulfur content on the determination of sulfur spot were investigated.Methods:Sodium thiosulfate titrant was used to calibrate the standard sodium sulfide solution with different opening time,To determine the sulfur content and compare the sulfur spots prepared by standard sodium sulfide solution before and after calibration.Results:The longer the opening time,the more serious the deliquescence of sodium sulfide reagent,the lower the sulfur content,and the shallower the standard sulfur spot.Conclusion:After unsealing,sodium sulfidewill slowly oxidize and deliquescence to form other sulfur compounds and release hydrogen sulfide gas to reduce its sulfur content.When using sodium sulfide as reference material for volatile sulfide determination,it is necessary to calibrate sodium sulfide to ensure the accuracy of results.