Simultaneous Determination of Sulfanilamide and Furosemide by Using Derivative Spectrophotometry

Abstract

A simple, precise and accurate spectrophotometric method has been developed for simultaneous estimation of sulfanilamide and furosemide in their mixture by using first and second order derivative method in the ultraviolet region. The method depends on first and second derivative spectrophotometry, with zero-crossing and peak to base line and peak area measurements. The first derivative amplitudes at 214, 238 and 266 nm were selected for the assay of sulfanilamide and 240, 260, 284, 314 and 352 nm for furosemide. Peak area at 201222, 222-251 and 251-281 nm selected for estimation of sulfanilamide and at 229-249, 249270, 270-294, 294-333 and 333-382 nm for furosemide. The second derivative amplitudes at 220, 252 and 274 nm for sulfanilamide and 248, 272, 292, 334, and 364 nm for furosemide. Peak area at 209-229, 239-262 and 262-285 nm for sulfanilamide and at 238-253, 262-281, 281-303, 315-353 and 353-383 nm for furosemide. The first derivative absorption at 270.5 nm (zero cross point of furosemide) was used for determination of sulfanilamide and 322.5 and 352 nm (zero cross point of sulfanilamide) for determination of furosemide. The second derivative absorption at 261 and 283.3 nm (zero cross point of furosemide) was used for determination of sulfanilamide and 266, 334 and 364 nm (zero cross point of sulfanilamide) for determination of furosemide. The linearity was established over the concentration range of 1-35 μg/ml and 1-60 μg/ml for sulfanilamide and furosemide with correlation coefficient R2 0.9991 and 0.9995 respectively. Accuracy and precision of the determination method on the various amounts of sulfanilamide and furosemide with known concentrations were evaluated in their binary mixtures. The proposed method has been successfully applied to the estimation of sulfanilamide in its synthetic samples and furosemide in its drug tablets.