A pulsed sequential injection analysis flow system for the fluorimetric determination of indomethacin in pharmaceutical preparations

The enhanced sample/reagent mixing provided by the controlled pulsed flow was favourably applied in the implementation of a SIA methodology for the fluorimetric determination of indomethacin in pharmaceutical preparations upon alkaline hydrolysis in micellar medium. Linear calibration plots were obtained for indomethacin concentrations up to 10−5 mol l−1 with a 3σ detection limit of about 1.6 × 10−8 mol l−1. The obtained results complied with those furnished by the reference procedure (RD ≤ 2.3%) and exhibited good reproducibility (RSD < 1.2%, n = 15). Sampling rate was about 30 samples per hour.