Evaluation of the xenon arc lamp as a light source for aquatic photodegradation studies: Comparison with natural sunlight

摘要

AbstractThe use of xenon arc illumination as a substitute for natural sunlight in the aqueous photolysis test was evaluated by exposing four chemicals to both xenon arc and sun illumination. The chemicals were chosen based on their known photodegradation half‒lives, absorption maxima and ease of analysis. The percentage of chemical remaining at the end of the exposure period and the photodegradation half‒life were compared for each chemical by light source. To compensate for the variability in natural sunlight intensity during an exposure period, data were also compared based on total light exposure, i.e., the intensity of exposure integrated over time. Photolysis of the four chemicals under the xenon arc lamp compared favorably with that under sunlight. Based on the results of this study, xenon arc illumination is equivalent to sunlight for use in determining aqueous photolysis ra