Weber Jan, Halsall Crispin J, Wargent Jason J, Paul Nigel D
Lancaster Environment Centre, Lancaster University, Lancaster, UK.
J Environ Monit. 2009 Mar;11(3):654-9. doi: 10.1039/b811387d. Epub 2009 Jan 8.
Aqueous solutions of fenitrothion and methyl parathion were photochemically degraded in an Atlas Suntest solar simulator (500 W m(-2)) as well as under ambient sunlight at Lancaster University (June & August 2007, 54 degrees N) and the degradation kinetics and disappearance quantum yields are reported. Fenitrothion degradation confirmed to first order kinetics (r(2) = 0.90-0.99) with a half-life range of 4.9 h-5.3 h, shorter than previously reported studies. In contrast, methyl parathion did not show significant degradation over the duration of these experiments. Light irradiances were monitored with a spectroradiometer during the Suntest simulator and outdoor experiments. The filtered-xenon arc lamp of the Suntest yielded spectral irradiances comparable to natural sunlight in the UVB and UVA wavelength range (280-400 nm), but with higher irradiances in the visible region (400-750 nm). Nonetheless, as both compounds have light absorption spectra at wavelengths < 400 nm, then the half-lives and disappearance quantum yields were similar between the Suntest and natural sunlight, and demonstrated that the Suntest is suitable for environmentally-relevant photochemical degradation experiments.
杀螟硫磷和甲基对硫磷的水溶液在阿特拉斯阳光试验箱（500 W m(-2)）中以及在兰卡斯特大学的自然阳光下（2007年6月和8月，北纬54度）进行了光化学降解，并报告了降解动力学和消失量子产率。杀螟硫磷的降解符合一级动力学（r(2) = 0.90 - 0.99），半衰期范围为4.9小时至5.3小时，比先前报道的研究结果短。相比之下，在这些实验期间，甲基对硫磷没有显示出明显的降解。在阳光试验箱和户外实验期间，用分光辐射计监测光照强度。阳光试验箱的滤光氙弧灯在UVB和UVA波长范围（280 - 400 nm）产生的光谱辐照度与自然阳光相当，但在可见光区域（400 - 750 nm）辐照度更高。尽管如此，由于这两种化合物在波长< 400 nm处都有光吸收光谱，因此阳光试验箱和自然阳光之间的半衰期和消失量子产率相似，这表明阳光试验箱适用于与环境相关的光化学降解实验。
