Study on the color reaction of phenylfluorone with bis(methoxy carbonylethyl) tin dichloride and its application

In the acetic acid-acetate buffer solution at pH6.2 and in the presence of CTMAB,the bis(methoxy carbonylethyl)tin dichloride(abb.R 2SnCl 2)reacts with phenylfluorone(PF)to form a 1∶2 colored complex.The maximum absorption of the complex is at 560nm and the apparent molar absorptivity of the complex is 3.19×10 4 L·mol -1 ·cm -1 .Beer’s law is obeyed in the range of 0-2.6mg/L for Sn in R 2SnCl 2.The proposed method has been applied to the determination of R 2SnCl 2 in polyvinyl chloride intermediate with satisfactory results.The relative standard deviation is 0.76%-1.13% and the recovery is in the range of 98.5%-101.0%.The mechanism of color reaction of R 2SnCl 2 with PF has been discussed.