Some physical parameters influencing the comprehensive evaluation of kinetic data in photochemical reactions and its application in the periodate-chemistry

•Comparing the emitted light of lamps by an external detector and some corrections.•Emission spectra measured by diode-array instruments itself cannot be directly used.•Determination of the actual irradiation time may be a complex problem in some cases.•Photochemical decomposition of orthoperiodate.•Photochemical decomposition of periodate does not affect the measured absorbance.