Conversion of cellulose into platform chemical 5-hydroxymethylfurfural (HMF) in water-tetrahydrofuran (THF) co-solvents under acidic condition was studied. 38.6% of HMF was obtained with low cellulose concentratio...Conversion of cellulose into platform chemical 5-hydroxymethylfurfural (HMF) in water-tetrahydrofuran (THF) co-solvents under acidic condition was studied. 38.6% of HMF was obtained with low cellulose concentration of 2.4wt%, but levulinic acid (LA) and solid humins became the main products with high cellulose concentration. The soluble byproducts were analyzed by high performance liquid chromatography/multiple stage tandem mass spec-trometry, and chemicals with formula of C9H16O4、 C10H14O4、 C11H12O4、C12H10O5 and C12H16O8 were detected. THF could participate in the reaction via ring-opening into 1,4-butanediol followed by esterification with LA into C9H16O4 or etherification with HMF into C10H14O4. C11H12O4 was formed by esterification of HMF with LA, C12H10O5 was formed by self-etherification of HMF, while C12H16O8 was formed by acetalization of HMF with glucose. Self-etherification of HMF and etherification of HMF with 1,4-butanediol were identified as two main side reactions.展开更多
目的:建立HPLC同时测定安息香中香草醛、松柏醛和trans-[四氢-2-(4-羟基-3-甲氧基苯基)-5-氧代呋喃-3-基]甲基苯甲酸酯含量的方法。方法:采用Phenomenex Luna C18(2)色谱柱(4.6 mm×250 mm,5μm),以甲醇-水为流动相,在1.0 m L·...目的:建立HPLC同时测定安息香中香草醛、松柏醛和trans-[四氢-2-(4-羟基-3-甲氧基苯基)-5-氧代呋喃-3-基]甲基苯甲酸酯含量的方法。方法:采用Phenomenex Luna C18(2)色谱柱(4.6 mm×250 mm,5μm),以甲醇-水为流动相,在1.0 m L·min-1的流速下,对样品进行梯度洗脱,并在280 nm波长处测定这3种化学成分的含量。结果:3种成分均能达到基线分离,且线性关系良好,加样回收率分别为99.51%,101.25%,100.71%。结论:该方法灵敏、准确、具有良好的稳定性和重复性,可用于同时测定安息香中这3种化学成分的含量,为安息香的质量控制研究提供一定参考。展开更多
基金This work was supported by the National Basic Research Program of China (No.2012CB215304), the National Natural Science Foundation of China (No.51376185 and No.51161140331), and the Natural Science Foundation of Guangdong Province (No.S2013010011612).
文摘Conversion of cellulose into platform chemical 5-hydroxymethylfurfural (HMF) in water-tetrahydrofuran (THF) co-solvents under acidic condition was studied. 38.6% of HMF was obtained with low cellulose concentration of 2.4wt%, but levulinic acid (LA) and solid humins became the main products with high cellulose concentration. The soluble byproducts were analyzed by high performance liquid chromatography/multiple stage tandem mass spec-trometry, and chemicals with formula of C9H16O4、 C10H14O4、 C11H12O4、C12H10O5 and C12H16O8 were detected. THF could participate in the reaction via ring-opening into 1,4-butanediol followed by esterification with LA into C9H16O4 or etherification with HMF into C10H14O4. C11H12O4 was formed by esterification of HMF with LA, C12H10O5 was formed by self-etherification of HMF, while C12H16O8 was formed by acetalization of HMF with glucose. Self-etherification of HMF and etherification of HMF with 1,4-butanediol were identified as two main side reactions.
文摘目的:建立HPLC同时测定安息香中香草醛、松柏醛和trans-[四氢-2-(4-羟基-3-甲氧基苯基)-5-氧代呋喃-3-基]甲基苯甲酸酯含量的方法。方法:采用Phenomenex Luna C18(2)色谱柱(4.6 mm×250 mm,5μm),以甲醇-水为流动相,在1.0 m L·min-1的流速下,对样品进行梯度洗脱,并在280 nm波长处测定这3种化学成分的含量。结果:3种成分均能达到基线分离,且线性关系良好,加样回收率分别为99.51%,101.25%,100.71%。结论:该方法灵敏、准确、具有良好的稳定性和重复性,可用于同时测定安息香中这3种化学成分的含量,为安息香的质量控制研究提供一定参考。