This standard specifies the determination method of acidity, ph value and titration value of industrial acrylonitrile, which is suitable for the detection of acidity and ph value in industrial acrylonitrile. The minimum detection concentration of acidity is 1 mg/kg (based on acetic acid). This part describes in detail the reagents, equipment and determination steps used in the analysis process, and emphasizes the danger of acrylonitrile and the safety protection measures in operation. It is an important specification to ensure the quality control of industrial acrylonitrile.