Amperometric determination of acetylsalicylic acid in drugs by batch injection analysis at a copper electrode in alkaline solutions

This paper describes the determination of acetylsalicylic acid (ASA) as salicylate (SA) in pharmaceutical formulations by using amperometric detection with copper electrodes in 0.10 mol l−1 NaOH solution. Batch injection analysis (BIA) was explored for this application. The system exhibited sharp current response peaks, rapid washout and excellent repeatability. A large linear dynamic range from 1 to 1000 μmol l−1 was obtained by using an injected volume of 100 μl, with a detection limit of 0.48 μmol l−1. R.S.D. of 0.37% for 30 repetitive (1×10−4 mol l−1) injections and sampling frequency of 60 h−1 were achieved. The results obtained using this system for ASA determination in seven different drug samples compared well with those found by spectrophotometry (Trinder test).