Flow-injection determination of cinnarizine using surfactant-enhanced permanganate chemiluminesence

Chemiluminescence (CL) of permanganate system in the presence of polyphosphoric acid (PPA), ethanol and Tween 60 was investigated and implemented using flow-injection analysis (FIA) to determine cinnarizine (C) in pharmaceutical preparations. Five hundred microliter samples were injected and the sample throughput was 130 h−1. Preliminary experiments identified Tween 60 as the surfactant of choice, improving the detection limit of the CL system 20-fold. Optimum CL signals were given using 7.5×10−4 mol l−1 potassium permanganate in 0.02 mol l−1 polyphosphoric acid as the oxidant stream and a carrier stream of 10% (v/v) of ethanol in aqueous 1.5×10−3 mol l−1 Tween 60 with a total flow rate of 7.6 ml min−1. The calibration graph was linear over the range 0.5–6.0 μg ml−1 (r=0.9963, n=7). The detection limit (3σ) was 18 ng ml−1 and the percentage recovery of spiked tablet solutions was 98.4–100.2.