Flow-injection spectrophotometric determination of frusemide or sulphathiazole in pharmaceuticals.

Two sensitive and fast flow-injection spectrophotometric methods are proposed for the determination of frusemide or sulphathiazole based on the formation of coloured complexes between these compounds and Pd(II) at pH 5.0 and 55 degrees C. Using the peak height as a quantitative parameter, frusemide or sulphathiazole was determined at 410 nm over the range 2.0 x 10(-5)-4.0 x 10(-4) M or 5.0 x 10(-5)-3 x 10(-4) M, respectively. The methods were applied to the determination of these sulphonamides in pharmaceuticals.