SIMPLE AND FAST HPLC METHOD FOR THE DETERMINATION OF TRIAMTERENE AND HYDROXYTRIAMTERENESULPHATE IN PLASMA AND URINE

Determination of triamterene (T) and hydroxytriamterenesuIphate (HTS) in plasma and urine requires a very sensitive and selective method. As both of the substances are highly hydrophilic, it is hardly feasible to carry out an extraction. The method described obviates the need for pre-cleansing of samples. Plasma and urine samples, diluted with wate r, are directly injected into the HPLC-column and analysed. For the de tection of both of the substances fluorescence was used. The use of a Spherisorb-NH2-column with a mobile phase, consisting only of a buffer solution in water, makes it possible to dispense with protein precipi tation of plasma. Both substances were analysed within 2 minutes in a single run. Detection limits of 1 ng T and 20 ng HTS/ml plasma as requ ired in practice, were obtained without any difficulties. Referring to the precision of this method with plasma samples, the variation coeff icient was below 3 % with HTS in the range of 20 to 1100 ng HTS/ml. Da y to day variation showed with T in plasma values of smaller than 7 % in the range of 1 to 100 ng/ml.