DIRECT DETERMINATION OF TRIAMTERENE IN URINE BY MATRIX ISOPOTENTIAL SYNCHRONOUS FLUORESCENCE SPECTROMETRY

A new method for the determination of triamterene for concentrations b etween 10 and 1000 ng ml(-1) by means of matrix isopotential synchrono us fluorescence spectrometry and derivative techniques is proposed. Th is new method is useful for the determination of compounds in samples with unknown background fluorescence, such as triamterene in urine, wi thout the need of tedious pre-separation. The determination was perfor med in an aqueous medium adjusted at a pH value of 6.2, provided by ad ding sodium citrate-citric acid buffer solution. Since triamterene is widely used as a doping substance in sport, the method was successfull y applied to the determination of triamterene in urine. Better sensiti vity and repeatability are achieved for these matrices with the propos ed method than with the fluorimetric ones described in the literature. An extensive statistical analysis has been developed to all calibrati on graphs. This treatment includes robust regression such as least med ian of squares which also detects outliers and leverage points. The we ighted least squares regression has been applied to find the more exac t straight line which fits the experimental data. The error propagatio n has been used for the calculation of the detection Limit, determinat ion limit and the repeatability of the method.