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Direct inlet probe atmospheric pressure photo and chemical ionization coupled to ultra-high resolution mass spectrometry for the description of lignocellulosic biomass
摘要： Lignocellulosic biomass, in particular wood, is a complex mixture containing cellulose, hemicellulose, lignin, and other trace compounds. Chemical analysis of these biomasses, especially lignin components, is a challenge. Lignin is a highly reticulated polymer that is poorly soluble and usually requires chemical, enzymatic, or thermal degradation for its analysis. Here, we studied the thermal degradation of lignocellulosic biomass using a direct insertion probe (DIP). DIP was used with two ionization sources: atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) coupled to ultra-high-resolution mass spectrometry. Beech lignocellulosic biomass sample were used to develop the DIP-APCI/APPI methodology. Two other wood species (maple and oak) were analyzed after optimization of DIP parameters. The two ionization sources were compared at first and showed different response towards beech sample, according to the source specificity. APPI was more specific to lignin degradation compounds, whereas APCI covered a larger variety of oxygenated compounds, e.g., fatty acids, polyphenolics compounds, in addition to lignin degradation products. The study of the thermo-desorption profile gave information on the different steps of lignocellulosic biomass pyrolysis. The comparison of the three feed sample types (oak, maple, and beech), using principal component analysis (PCA) with DIP-APCI experiments, showed molecular level differences between beech wood pellets and the two others wood species (maple and oak).
关键词： high-resolution mass spectrometry,APPI,APCI,direct inlet probe,biomass
更新于2025-09-19 17:13:59
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Synthesis of TiO2/SiO2-B2O3 Ternary Nanocomposites: Influence of Interfacial Properties on their Photocatalytic Activities with High Resolution Mass Spectrometry Monitoring
摘要： An investigation on unusual interface properties of unprecedented ternary composites, formed by the inclusion of assorted proportions of B2O3 into TiO2/SiO2 structure, is conducted herein. The influences of B2O3 content and calcination temperature were evaluated. The precursor TiO2/SiO2 material was synthesized via a simple sol-gel procedure that was followed by B2O3 inclusion via maceration and calcination. The materials were fully characterized and their photocatalytic performance to degrade the Indigo Carmine dye investigated. The material prepared with a B/Ti molar ratio of 1 and at calcination temperature of 350 °C (B1-350) showed the best performance, with a superior photocatalytic activity than that of commercial TiO2. The presence of B2O3-TiO2-SiO2 interfaces in the structure of such material was of critical importance in producing a material with these attractive features. Finally, high resolution mass spectrometry monitoring allowed for the characterization of the main degradation products formed under these conditions.
关键词： high resolution mass spectrometry,degradation of Indigo Carmine,B2O3-TiO2-SiO2 ternary nanocomposites,photocatalytic activity,by-products characterization,structural defects
更新于2025-09-04 15:30:14