Università degli Studi di Torino, Dipartimento di Chimica, Via Pietro Giuria 5-7, 10125 Torino, Italy.
Water Res. 2013 Oct 15;47(16):6109-21. doi: 10.1016/j.watres.2013.07.031. Epub 2013 Aug 2.
The harmful compound 4-isobutylacetophenone (IBAP) can be formed photochemically from the anti-inflammatory drug ibuprofen (IBP), upon direct photolysis (yield 25 ± 7%, μ ± σ), reaction with ·OH (yield 2.3 ± 0.1%) and reaction with triplet states of chromophoric dissolved organic matter, (3)CDOM* (yield 31 ± 4%). In the latter case, anthraquinone-2-sulphonate was used as CDOM proxy. The three processes would account for most of the photochemical transformation of IBP and IBAP in surface waters. IBAP formation from IBP involves the propanoic acid chain, which is more reactive than the aromatic ring as shown by quantum mechanical calculations. IBAP is expected to undergo slightly faster photochemical transformation than IBP in surface waters, with a modelled pseudo-first order rate constant that is higher by 1.5-1.9 times compared to IBP. Due to fairly high formation yields and depending on IBP emission scenarios, photochemical modelling suggests that IBAP could reach concentration values up to ~15% of IBP in surface waters, thus being a potentially important transformation intermediate. This issue prompts for the need of field studies that provide information on IBAP environmental occurrence, which is virtually unknown at the present moment.
有害化合物 4-异丁基苯乙酮（IBAP）可由抗炎药布洛芬（IBP）经光化学直接光解（产率 25±7%，μ±σ）、与·OH 反应（产率 2.3±0.1%）和与发色溶解有机物的三重态（3）CDOM*（产率 31±4%）反应生成。在后一种情况下，蒽醌-2-磺酸盐被用作 CDOM 的替代物。这三个过程将占布洛芬和 IBAP 在地表水中光化学转化的大部分。IBAP 是由 IBP 形成的，涉及丙酸链，这比芳香环更具反应性，这是由量子力学计算表明的。预计 IBAP 在地表水中的光化学转化速度略快于 IBP，模型化的拟一级速率常数比 IBP 高 1.5-1.9 倍。由于相当高的生成产率，并且取决于 IBP 的排放情景，光化学模拟表明 IBAP 可能在地表水中达到高达 IBP 浓度的 15%左右，因此它是一种潜在的重要转化中间产物。这一问题促使需要进行实地研究，提供 IBAP 环境出现的信息，目前这方面几乎是未知的。
