Figure 3

First derivative UV absorption spectra of 40 μg mL−1 MEL (black) and 700 μg mL−1 BUP (red) in 0.3% SDS showing wavelength selection in DWD method for determination of BUP.

First derivative UV absorption spectra of 40 μg mL−1 MEL (black) and 700 μg mL−1 BUP (red) in 0.3% SDS showing wavelength selection in DWD method for determination of BUP.