Quantification of Unimolecular Photoreaction Kinetics: Determination of Quantum Yields and Development of Actinometers—The Photodegradation Case of Cardiovascular Drug Nisoldipine

Figure 1

Evolution of the electronic absorption spectra of 5.88 × 10⁻⁵M NIS in ethanol subjected to a continuous irradiation with a 390 nm monochromatic beam (total irradiation time 2000 s at a radiant power of  einstein.s⁻¹.dm⁻³). The arrows indicate the direction of the peaks’ evolution during the photoreaction and the vertical lines cross the spectra at the isosbestic points (232, 259, and 320 nm).