Use of Dimethyl Silicone Oil for Defoaming in the Measurement of Aniline
消泡剂硅油Ⅰ在苯胺测定中的应用

This paper deals with the use of a dimethyl silicone oil (Silicone Oil I ) as a defoaming agent in the measurement of aniline present in a textile dyeing and printing wastewater which has a quite dark colour and a higher content of phenols. In the pre-distillation-diazotization-colorimetric determination of the above aniline, a large volume of foams formed during the distillation is an important factor affecting the precision of results and can be defoamed by adding the above silicone oil. It has been found that the addition of 0. 05-0. 5ml of silicone Oil I 100ml of water sample can give a desirable result. Sili- cone Oil I has a stable property, will not be vaporized out with steam and will not interfere with the measure-to ment. The recovery of standard reference added is 91. 1-97. 3% and the yield by distillation is 96% on average,