Pyrocatechol Violet-CPB Spectrophotometric Determination of Tin in Copper Alloy

The coloring reaction between catechol purple and tin was studied,a determination method of tin in copper alloy by spectrophotometry was established.The results showed that in ascorbic acid solution,and in the presence of surfactant cetyl pyridinium bromide(CPB),the tin could forms blue complex with catechol purple,the complex has maximum absorption at 644nm,its apparent molar absorptivity is 1.1×105L·mol-1·cm-1.Beers's law is obeyed in the range of 2—20μg in the solution of 25 mL for tin.The method is simple and high sensitivity,The method is aeeurate and quiek,The method can be applied to the determination of tin in copper alloy,and the determination results are agreement with the standard values.