Black locust (Robinia pseudoacacia L.), beech (Fagus sylvatica L.), aspen (Populus tremula L.) and sessile oak (Quercus petraea Liebl.) hardwood samples were irradiated by a strong ultraviolet (UV) emitter mercury lamp at 50 °C. Other series of specimens were exposed to a combined treatment of UV irradiation and water leaching. Ratio of UV radiation and water leaching time was 2:1. While the total duration of UV radiation was 20 days for both test series that of water leaching was 10 days. IR measurement was taken after both UV radiation and water leaching to monitor both effects separately. Lignin degradation proved to be more intensive in leached samples than in purely UV-irradiated samples. Guaiacyl and syringyl lignin showed similar degradation properties. Unconjugated carbonyl groups generated by the photodegradation were the most sensitive chemical components to leaching. Photodegradation generated two absorption bands of unconjugated carbonyl groups at around 1710 and 1760 cm−1 wavenumbers. The band at 1760 cm−1 was much more sensitive to water leaching than the band at 1710 cm−1. Three to ten days of water leaching was enough to remove all unconjugated carbonyls generated by the photodegradation, depending on the species. Sessile oak was the most sensitive species to water leaching, whereas black locust proved to be the most stable against both photodegradation and water leaching. Water was able to leach out unconjugated carbonyl groups (absorbing at 1745 cm−1) originally present in all investigated wood species.

中文翻译：

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红外光谱监测水对光降解硬木树种的浸出效应

刺槐 (Robinia pseudoacacia L.)、山毛榉 (Fagus sylvatica L.)、白杨 (Populus tremula L.) 和无柄橡木 (Quercus petraea Liebl.) 硬木样品用 50° 强紫外线 (UV) 发射器汞灯照射C。将其他系列的样品暴露于紫外线照射和水浸出的组合处理中。紫外线辐射与水浸出时间之比为2:1。两个测试系列的紫外线辐射总持续时间为 20 天，而水浸出的时间为 10 天。红外测量是在紫外线辐射和水浸出后进行的，以分别监测这两种影响。事实证明，浸出样品中的木质素降解比纯紫外线照射的样品更强烈。愈创木酰基和丁香基木质素显示出相似的降解特性。光降解产生的未共轭羰基是对浸出最敏感的化学成分。光降解在 1710 和 1760 cm-1 波数附近产生了两个未共轭羰基的吸收带。1760 cm-1 处的波段比 1710 cm-1 处的波段对水浸出更敏感。三到十天的水浸出足以去除光降解产生的所有未共轭羰基化合物，具体取决于物种。无柄橡树是对水浸出最敏感的物种，而刺槐被证明对光降解和水浸出最稳定。水能够浸出所有研究的木材物种中最初存在的未共轭羰基（在 1745 cm-1 处吸收）。光降解在 1710 和 1760 cm-1 波数附近产生了两个未共轭羰基的吸收带。1760 cm-1 处的波段比 1710 cm-1 处的波段对水浸出更敏感。三到十天的水浸出足以去除光降解产生的所有未共轭羰基化合物，具体取决于物种。无柄橡树是对水浸出最敏感的物种，而刺槐被证明对光降解和水浸出最稳定。水能够浸出所有研究的木材物种中最初存在的未共轭羰基（在 1745 cm-1 处吸收）。光降解在 1710 和 1760 cm-1 波数附近产生了两个未共轭羰基的吸收带。1760 cm-1 处的波段比 1710 cm-1 处的波段对水浸出更敏感。三到十天的水浸出足以去除光降解产生的所有未共轭羰基化合物，具体取决于物种。无柄橡树是对水浸出最敏感的物种，而刺槐被证明对光降解和水浸出最稳定。水能够浸出所有研究的木材物种中最初存在的未共轭羰基（在 1745 cm-1 处吸收）。三到十天的水浸出足以去除光降解产生的所有未共轭羰基化合物，具体取决于物种。无柄橡树是对水浸出最敏感的物种，而刺槐被证明对光降解和水浸出最稳定。水能够浸出所有研究的木材物种中最初存在的未共轭羰基（在 1745 cm-1 处吸收）。三到十天的水浸出足以去除光降解产生的所有未共轭羰基化合物，具体取决于物种。无柄橡树是对水浸出最敏感的物种，而刺槐被证明对光降解和水浸出最稳定。水能够浸出所有研究的木材物种中最初存在的未共轭羰基（在 1745 cm-1 处吸收）。