FLOW INJECTION CHEMILUMINESCENT ANALYSIS OF ISONIAZID BY DIRECT HEXACYANOFERRATE(III) OXIDATION

A very simple chemiluminescence (CL) flow system is described for the determination of isoniazid based on its direct oxidation by hexacyanoferrate(III) solution in an alkaline media. The system responds linearly to isoniazid concentration in the range 0.05–2 µg/mL with a detection limit (3s) of 0.01 µg/mL. Relative standard deviation (RSD) is 1.6% for 0.5 µg/mL of isoniazid (n = 11). The system has been successfully applied to the determination of isoniazid in pharmaceutical preparations. The measurement could be performed in 30 s with sampling rate of 120 times per hour.