The near-UV absorption constants for nitrite ion in aqueous solution

The UV decadic molar absorptivities of nitrite ion in water were determined between 290 and 400 nm in 2-nm increments. The measured maximum absorptivity of 22.93 M cm−1 at 354 nm is in agreement with previous results. Using absorptivities obtained in this wavelength range, we calculated the first-order rate constant for the formation of OH radicals by the photolysis of aqueous nitrite in summer noon sunlight at 40°N. The resulted rate constants, 5.2 × 10−5 s−1 for surface water and 1.04 × 10−4 s−1 for cloud and rain water droplets, are twice the previously reported values. The environmental significance of these results is discussed briefly.