In this study, derivative UV spectrophotometric methods were developed for the analysis of diflunisal, which is used as a nonsteroidal anti-inflammatory drug. Analysis wavelengths of diflunisal for the first and second order derivative UV spectrophotometric methods were obtained as 235.6 nm and 228.8 nm, respectively. The linearity ranges were found as 1.0-25.0 μg mL-1 for the first order and 1...