Goldstein Sara, Aschengrau Dorit, Diamant Yishay, Rabani Joseph
Department of Physical Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Environ Sci Technol. 2007 Nov 1;41(21):7486-90. doi: 10.1021/es071379t.
Methanol is used to measure the yield of *OH radicals produced in the photolysis of H2O2 in aqueous solutions. The UV photolysis of H202 generates *OH radicals, which in the presence of methanol, oxygen, and phosphate buffer form formaldehyde, namely, phi(HCHO) = phi(*OH). The quantum yield of *OH has been redetermined in view of literature inconsistencies resulting in phi(*OH) = 1.11 +/- 0.07 in the excitation range of 205-280 nm. The constancy of phi(*OH) and the ease and sensitivity of the formaldehyde product analysis makes the H2O2/CH3OH system suitable for polychromatic UV actinometry. In addition, the relatively low cost of the main components and the possibility of destroying the methanol before disposal qualify the system for both monochromatic and polychromatic actinometry in a large volume of water. The H2O2/CH3OH system was applied in different commercial UV photoreactors.
甲醇用于测量水溶液中过氧化氢光解产生的OH自由基的产率。过氧化氢的紫外光解产生OH自由基，在甲醇、氧气和磷酸盐缓冲液存在的情况下，*OH自由基会生成甲醛，即φ(HCHO)=φ(*OH)。鉴于文献中的不一致性，*OH的量子产率已重新测定，结果发现在205-280nm的激发范围内，φ(*OH)=1.11±0.07。*OH量子产率的稳定性以及甲醛产物分析的简便性和灵敏性，使得H2O2/CH3OH体系适用于多色紫外光量计测量。此外，主要成分成本相对较低，且在处理前有可能破坏甲醇，这使得该体系适用于大量水体中的单色和多色光量计测量。H2O2/CH3OH体系已应用于不同的商用紫外光反应器中。
