| 摘要 |
<p>To produce technical TRIFLURALIN with a nitrosoamine content not exceeding 1 ppm, for use as a herbicide, DINITRO-PCBT free from nitrosating agents is prepared by a process in which DINITRO-PCBT is treated with an aqueous bisulphite solution having a S02 concentration of between 1% and 5% at a pH of between 1 and 3, at a temperature of between 50.degree. and 100.degree.C for a time of between 1 and 3 hours. The organic layer is then separated from the aqueous layer, and the acidity and last traces of the bisulphite solution are eliminated from the organic layer by means of an aqueous alkaline solution.</p> |
