Differential Pulse Polarographic Determination of Furosemide (lasimex) in Human Serum and Urine

The present work involves a study of the polarographic behavior of pure Furosemide(lasimex) by direct method in aqueous solution , which gives a two well defined reduction peaks, the main peak at a potential (-0.196) volts and the other small peak at (-0.236) volts in phosphate buffer (pH=3).The calibration of Furosemide was constructed in phosphate buffer (pH=3) the calibration curves in the potential (-0.196) volts were observed in the range of concentration (6.8310-5 - 9.9010-5) M with a correlation coefficient (0.9884), and second in the range of concentration (10.5110-5-12.3410-5) M with a correlation coefficient (0.9919).
The calibration curve of Furosemide in the presence of human blood serum was studied in the potential (-0.187) volts and range concentration of current (7.4410-5-15.3810-5) M with a correlation coefficient (0.9971).
The calibration curve of Furosemide in presence of urine in the potential (-0.084) volt and range of concentration (7.4210-5-12.3110-5) M with a correlation coefficient (0.9960).
The method was successfully applied to the determination of Furosemide in tablets in aqueous solution and in the presence of valium voltammetrically with out interferences.