\label{consuptionprofile}
Time evolution of reactants and photoproducts concentrations in air-equilibrated aqueous solutions irradiated under sunlight in clear sky days in La Plata city. The exposures were carried out within one hour around solar noon for two consecutive days near spring equinox (on September 23$^{rd}$ and 24$^{th}$ 2013, for solutions of Bip and H$_{2}$Bip, respectively). Concentrations were determined by HPLC analysis. (a) [Bip]$_{0}$=93$\mu$M; (b) [H$_{2}$Bip]$_{0}$=70$\mu$M, inset: time evolution of the areas of chromatographic peaks corresponding to the dimers of H$_{2}$Bip.