油溶性清蜡剂中二硫化碳的测定方法

Method of determining CS_2 in oil based paraffin remover

清蜡剂中加入二硫化碳虽能提高清蜡效率,但会严重腐蚀金属设备。为此,研究了简单易行的测定清蜡剂中二硫化碳含量的方法。该方法是将油基清蜡剂中的二硫化碳用氮气吹出后,用吸收剂吸收,通过测定二硫化碳和吸收剂反应产物来确定清蜡剂中二硫化碳含量。为提高二硫化碳的吸收效率,设计了新型吸收装置,在此基础上对比分析了不同二硫化碳吸收剂的效果。结果表明,用二乙胺-乙酸铜的乙醇溶液作为吸收剂,由于Cu2+过量时会对标准曲线产生干扰,从而影响二硫化碳含量的测定;氢氧化钾的甲醇溶液作吸收剂对二硫化碳的吸收速度比乙二胺的乙醇溶液快,吸收效率最高可达98.9%,且二硫化碳与氢氧化钾反应产物的吸光度在120min内保持稳定。

The addition of CS_2 into oil solvent can enhance its efficiency to dissolve paraffin,but it will result in the problem of metal corrosion. So, a method to determine the content of CS_2 in oil based paraffin remover is suggested in this paper. In this method, the content of CS_2 can be determined after it is swept from the oil based paraffin remover and absorbed by absorbents. So, the key to this method is to improve the efficiency and analysis accuracy of absorbing CS_2. In this paper, for absorbing CS_2, we designed a new type of units in the base of air sampler, and compared the standard absorbing curve and efficiency of different absorbers by spectrophotometric method. The results confirm that the alcohol solution of diethyl amine-copper acetate shouldn' t be selected to absorb CS_2 due to the disturbance of redundant Cu_2+; compared to alcohol-ethylenediamine solution, a higher rate of CS_2 absorption is obtained by using the system of methanol-potassium hydroxide and the corresponding product of absorbing is chemically stable in 2 hours. Moreover, with the self-designed setup and methanol-potassium hydroxide solution as absorbents, the adsorption efficiency of CS_2 is as high as 98% and the result has good repeatability.