Triamterene and piretanide analysis by fluorescence polarization

Polarization measurements have been used for the quantitative analysis of b inary mixtures of compounds which have overlapping luminescence spectra and different polarizations. This approach has been developed and applied to r esolve a binary mixture of two diuretic drugs: triamterene and piretanide. To promote long rotational relaxation times in order to decrease the depola rization of these small molecules the solutions have been made in glycerin. Satisfactory results have been obtained for both compounds. A linear dynam ic range 24-142 mug L-1 and 2.5-14.0 mg L-1, a detection limit of 23 mug L- 1 and 2.5 mg L-1 and a relative standard deviation of 10.0% and 6.7% (n=3) were calculated for triamterene and piretanide, respectively.