建立了一种利用胶束电动毛细管色谱-间接紫外检测法同时测定丙二酸、甲酸、酒石酸、苹果酸、琥珀酸、戊二酸、乙酸、乳酸和谷氨酸的新方法。以7.5mm o l/L邻苯二甲酸氢钾-1.5mm o l/L十六烷基三甲基溴化铵(用0.1m o l/L氢氧化钠调pH至6....建立了一种利用胶束电动毛细管色谱-间接紫外检测法同时测定丙二酸、甲酸、酒石酸、苹果酸、琥珀酸、戊二酸、乙酸、乳酸和谷氨酸的新方法。以7.5mm o l/L邻苯二甲酸氢钾-1.5mm o l/L十六烷基三甲基溴化铵(用0.1m o l/L氢氧化钠调pH至6.50)混合液作为电泳介质,检测波长为300nm,参比波长为210nm,未涂层弹性石英毛细管(50μm i.d.×64cm)为分离通道,在6m in内实现了9种酸的完全分离。9种有机酸的浓度与其峰面积在一定的范围呈良好的线性关系,检出限均低于1.5m g/L,迁移时间和峰面积的日内、日间相对标准偏差均小于6%。该法用于糖蜜酒精废液中有机酸的测定,结果令人满意,9种有机酸的样品加标回收率均在93%以上。展开更多
Spectroscopic characteristics of the β-fructosyltransferase(EC2.4.1.9 FTS) from Aspergillus oryzae GX0011 was studied by ultraviolet absorbance spectrum,fluorescence spectrum and circular dichroism.The enzyme exhibit...Spectroscopic characteristics of the β-fructosyltransferase(EC2.4.1.9 FTS) from Aspergillus oryzae GX0011 was studied by ultraviolet absorbance spectrum,fluorescence spectrum and circular dichroism.The enzyme exhibited that the characteristic peaks of ultraviolet absorbance spectrum,of fluorescence emission spectrum were at 280nm and 343nm.In low concentration of ,the fluorescence quenching was in line with the Sterm-Volmer’s equation and the percentage of Trp residue reacted by was 0.72.By comparing the fluorescence spectra of FTS substrate-perturbation,it was implied that some inner Trp residues participated in catalysis and might be involved in the active site of the enzyme.Furthermore,the secondary structures of FTS were quantitatively determined by circular dichroism.The relative percentage content of each secondary structure were:25.1±0.8% α-helix,5.3±2.3% β-sheet,31.4±1.5%β-turn and 38.2±1.1% random coil respectively.展开更多
文摘建立了一种利用胶束电动毛细管色谱-间接紫外检测法同时测定丙二酸、甲酸、酒石酸、苹果酸、琥珀酸、戊二酸、乙酸、乳酸和谷氨酸的新方法。以7.5mm o l/L邻苯二甲酸氢钾-1.5mm o l/L十六烷基三甲基溴化铵(用0.1m o l/L氢氧化钠调pH至6.50)混合液作为电泳介质,检测波长为300nm,参比波长为210nm,未涂层弹性石英毛细管(50μm i.d.×64cm)为分离通道,在6m in内实现了9种酸的完全分离。9种有机酸的浓度与其峰面积在一定的范围呈良好的线性关系,检出限均低于1.5m g/L,迁移时间和峰面积的日内、日间相对标准偏差均小于6%。该法用于糖蜜酒精废液中有机酸的测定,结果令人满意,9种有机酸的样品加标回收率均在93%以上。
文摘Spectroscopic characteristics of the β-fructosyltransferase(EC2.4.1.9 FTS) from Aspergillus oryzae GX0011 was studied by ultraviolet absorbance spectrum,fluorescence spectrum and circular dichroism.The enzyme exhibited that the characteristic peaks of ultraviolet absorbance spectrum,of fluorescence emission spectrum were at 280nm and 343nm.In low concentration of ,the fluorescence quenching was in line with the Sterm-Volmer’s equation and the percentage of Trp residue reacted by was 0.72.By comparing the fluorescence spectra of FTS substrate-perturbation,it was implied that some inner Trp residues participated in catalysis and might be involved in the active site of the enzyme.Furthermore,the secondary structures of FTS were quantitatively determined by circular dichroism.The relative percentage content of each secondary structure were:25.1±0.8% α-helix,5.3±2.3% β-sheet,31.4±1.5%β-turn and 38.2±1.1% random coil respectively.
