核磁共振中色谱分离原理及应用

发布时间：2018-10-21 16:03

【摘要】：核磁共振中色谱技术无需经过物理分离便可实现混合物中分析物的信号分离,已在混合物组分分离分析方面显示出良好的应用潜能。目前关于提升核磁共振色谱分析效果的研究还是相对较少,因此本文首先较系统考察有机溶剂对核磁共振中色谱分离效果的影响;接着,以十二烷基磺酸钠为虚拟固定相,拓展适用于该技术的分析物体系;最后,将核磁共振色谱分离技术应用于生物质转化实际应用体系中,展现出优于传统分析方法的特点。首先,本文选用氘代甲醇、氘代二甲基亚砜、氘代丙酮和氘代乙腈四种有机改性剂,以醇、酸和氨基酸等不同类型的化合物作为分析物模型体系,考察水相中不同体积分数的有机改性剂对核磁共振中色谱分离技术的影响。实验结果表明:前三种氘代试剂对分析物分离效果的影响具有共性,随着水相中加入氘代试剂体积分数的增加,分析物的扩散系数先减小后增大;而随着氘代乙腈体积分数的增加,分析物的扩散系数一直增加。氘代试剂的加入,在某种程度上改善了混合物之间的分离效果。其次,本文考察了十二烷基磺酸钠作为虚拟固定相,分离以下6组芳香族有机酸混合物的分离能力:(1)邻羟基苯甲酸、间羟基苯甲酸和对羟基苯甲酸;(2)苯甲酸、邻苯二甲酸和均苯三甲酸;(3)水杨酸、邻苯二甲酸和对甲苯磺酸;(4)对溴苯甲酸、水杨酸和对甲苯磺酸;(5)苯甲酸、邻苯二甲酸和对甲苯磺酸;(6)对溴苯甲酸、苯甲酸和对甲苯磺酸。实验结果表明:上述六组混合物均能在虚拟固定相的作用下实现信号分离,其信号分离原因为分析物与虚拟固定相的作用强度不同。最后,本文将核磁共振色谱技术应用到丁二酸实际发酵液中,通过测定发酵液中不同组分的扩散系数,并结合模型化合物的核磁信号,测定出发酵液中含有的主要物质为葡萄糖、丁二酸和乙酸。进一步对丁二酸实际发酵液进行qHNMR定量实验,实验结果得出,发酵液中目的产物丁二酸的含量为14 g/L,副产物乙酸的含量为11 g/L,计算结果与HPLC定量结果一致。
[Abstract]:The chromatographic technique in NMR can realize the signal separation of the analyte in the mixture without physical separation. It has shown good application potential in the separation and analysis of mixture components. At present, there is relatively little research on improving the analytical effect of NMR chromatography, so the effect of organic solvents on chromatographic separation in NMR is studied systematically, and then sodium dodecyl sulfonate is used as virtual stationary phase. Finally, the nuclear magnetic resonance chromatographic separation technology was applied to the practical application system of biomass conversion, which showed better characteristics than the traditional analytical methods. Firstly, four organic modifiers, such as deuterated methanol, deuterated dimethyl sulfoxide, deuterated acetone and deuterated acetonitrile, were used as the analytical model system. The effect of organic modifiers with different volume fraction in water phase on chromatographic separation in NMR was investigated. The experimental results show that the first three deuterium reagents have a common effect on the separation of analytes. With the increase of the volume fraction of deuterium reagents in the water phase, the diffusion coefficient of the analytes decreases first and then increases. However, with the increase of deuterated acetonitrile volume fraction, the diffusion coefficient of the analyte increases. The addition of deuterium reagents improves the separation of mixtures to some extent. Secondly, the separation ability of sodium dodecyl sulfonate as a virtual stationary phase for the separation of six groups of aromatic organic acid mixtures was investigated: (1) o-hydroxybenzoic acid, m-hydroxybenzoic acid and p-hydroxybenzoic acid, (2) benzoic acid, Phthalic acid and terephthalic acid; (3) salicylic acid, phthalic acid and p-toluenesulfonic acid; (4) p-bromobenzoic acid, salicylic acid and p-toluenesulfonic acid; (5) benzoic acid, phthalic acid and p-toluenesulfonic acid; (6) p-bromobenzoic acid, benzoic acid and p-toluenesulfonic acid. The experimental results show that the above six groups of mixtures can achieve signal separation under the action of the virtual stationary phase, and the reason for the signal separation is that the interaction intensity between the analyte and the virtual stationary phase is different. Finally, nuclear magnetic resonance chromatography was applied to the actual fermentation broth of succinic acid. The diffusion coefficient of different components in the fermentation broth was determined, and the nuclear magnetic signal of the model compound was combined. The main substances in fermentation broth are glucose, succinic acid and acetic acid. Further qHNMR quantitative experiments were carried out on the fermentation broth of succinic acid. The results showed that the content of succinic acid and acetic acid were 14 g / L and 11 g / L, respectively. The calculated results were in agreement with the quantitative results of HPLC.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O652.6

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