Assays - Triamterene and metabolite

Simple and fast HPLC method for the determination of Triamterene and Hydroxytriamterene sulfate in plasma and urine

Author: H.J. Mascher, M. Wasilewski
Publisher: J. Liqu. Chromatogr., 17 (1994), 1577-1585

Determination of triamterene (T) and hydroxytriamterenesulphate (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, dilutet with water, are directly injected into the HPLC-column and analysed. For the detection 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 precipitation of plasma. Both substances were analysed within 2 minutes in a single run. Detection limits of 1 ng/ml T and 20 ng/ml HTS in plasma as required in practice, were obtained without any difficulties. Referring to the precision of this method with plasma samples, the variation coefficient was below 3 % with HTS in the range of 20 to 1100 ng HTS / ml. Day to day variation showed with T in plasma values of smaller than 7 % in the range of 1 to 100 ng/ml.