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Determination of Lignin in Marine Sediment Using Alkaline Cupric Oxide Oxidation-Solid Phase Extraction-on-Column Derivatization-Gas Chromatography 被引量:10
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作者 ZHANG Ting LI Xianguo +3 位作者 SUN Shuwen LAN Haiqing DU Peirui WANG Min 《Journal of Ocean University of China》 SCIE CAS 2013年第1期63-69,共7页
Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters (TOMs) in marine environment. Extraction and derivatization of lignin oxidation products (LOPs) are crucial for ... Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters (TOMs) in marine environment. Extraction and derivatization of lignin oxidation products (LOPs) are crucial for accurate quantification of lignin in marine sediment. Here we report a modification of the conventional alkaline cupric oxide (CuO) oxidation method, the modification consisting in a solid phase extraction (SPE) and a novel on-column derivatization being employed for better efficiency and reproducibility. In spiking blanks, recoveries with SPE for the LOPs are between 77.84% and 99.57% with relative standard deviations (RSDs) ranging from 0.57% to 8.04% (n=3), while those with traditional liquid-liquid extraction (LLE) are from 44.52% to 86.16% With RSDs being from 0.53% to 13.14% (n=3). Moreover, the reproducibility is greatly improved with SPE, with less solvent consumption and shorter processing time. The average efficiency of on-column derivatization for LOPs is 100.8%±0.68%, which is significantly higher than those of in-vial or in-syringe derivatization, thus resulting in still less consumption of derivatizing reagents.Lignin in the surface sediments sampled from the south of Yangtze River estuary, China, was determined with the established method. Recoveries of 72.66% to 85.99% with standard deviation less than 0.01mg/10g dry weight are obtained except for p-hydroxybenzaldehyde. The lignin content ∑8 (produced from 10g dry sediment) in the research area is between 0.231 and 0.587mg. S/V and C/V ratios (1.028 ± 0.433 and 0.192±0.066, respectively) indicate that the TOMs in this region are originated from a mixture of woody and nonwoody angiosperm plants; the high values or (Ad/Al)v suggest that the TOMs has been highly degraded. 展开更多
关键词 LIGNIN alkaline cupric oxide SPE on-column derivatization marine sediments
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利用计算化学方法从HOMO轨道能量判断路易斯碱的强弱
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作者 陈欣宇 李子昊 +2 位作者 董立坤 蒋燮阳 张书宇 《化学教育(中英文)》 CAS 北大核心 2024年第14期29-35,共7页
以经典路易斯酸碱性比较问题为切入点,以羰基化合物为实例,从原理上探讨了一种通过计算分子HOMO轨道能量判断路易斯酸碱性的方法,帮助学生比较和分析路易斯碱的相对碱性大小,并对学生表现进行了有效评估。旨在通过此过程引导本科生借助... 以经典路易斯酸碱性比较问题为切入点,以羰基化合物为实例,从原理上探讨了一种通过计算分子HOMO轨道能量判断路易斯酸碱性的方法,帮助学生比较和分析路易斯碱的相对碱性大小,并对学生表现进行了有效评估。旨在通过此过程引导本科生借助现代化研究分析方法主动思考和加深对化学基础概念的理解,进而激发学生的学习兴趣。 展开更多
关键词 有机化学 羰基化合物 计算化学 相对碱性 HOMO轨道的能量
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