电位滴定法测定炼化装置高含硫冷凝水中的氯化物

Potentiometric Titration for Determination of Chloride in Condensed Water with High Sulfur in Refining Unit

某炼化装置工艺冷凝水浊度较大,成分复杂,由于含有大量的硫化物、氨氮等介质,对氯离子的测定造成严重干扰,影响腐蚀监测。提出了合适的前处理方法,消除了水样高硫含量和氨氮含量高物质的干扰,并采用电位滴定法测定,避免了水样色度、溶液酸碱度对滴定的影响,同时避免了采用人工滴定法因为指示剂的加入量过大或过小、操作者对滴定终点颜色误判等造成的误差,提高了测定的准确度。采用新方法测定,相对标准偏差最大为1.90%,实际样品的加标回收率为99.30%~103.93%。

The determination of chloride is greatly disturbed by high turbidity and complex media in condensed water sample of refining unit,thereby affecting corrosion monitoring.Pretreatment method is proposed to eliminate interference from water samples with high sulfur and ammonia.Potentiometric titration is applied to avoid influence brought by color and pH value of water sample.Meanwhile,human errors are eliminated and determination accuracy gets improved accordingly.With the new methods,maximum relative standard deviation is 1.90%,sample recovery is between 99.30%-103.93%.