【作者】 刘春梅；

【导师】 张栩；

【作者基本信息】 北京化工大学 ， 生物化工， 2009， 硕士

【摘要】 苏氨酸为人体必需的八种氨基酸之一,在食品、医药和饲料行业具有极其重要的作用。苏氨酸等电母液里含有7%的苏氨酸,因此提取苏氨酸母液中的苏氨酸有重要经济价值,既可使苏氨酸母液的价值得到增值,同时减少母液排放对环境的污染。本论文研究离子交换法分离提取等电母液中的苏氨酸,旨在为苏氨酸母液提供新的、且有效的处理方法,也为应用于工业生产提供一定的技术基础。建立了苏氨酸定量测定的方法。通过茚三酮比色法、离子色谱-电导检测法测定苏氨酸,比较这两种方法的优缺点,确定了离子色谱-电导检测法测定苏氨酸的分析方法。采用4.0mmol·L^-1的酒石酸和1.0mmol·L^-1的2,6-吡啶二羧酸为淋洗液等度洗脱,流速为1.0 mL·min^-1,使用C2 150/4.0阳离子色谱分析柱和电导检测器,实现不经柱前衍生化即可测定混合氨基酸的方法;考察样品中普通无机阳离子和葡萄糖等非离子有机物对测定的影响。结果表明,同时测定苏氨酸、缬氨酸、异亮氨酸、苯丙氨酸四种氨基酸时的标准曲线线性相关系数均大于0.9993,方法具有较高的精密度和准确度,可以实现一些氨基酸的定性和定量检测;测定不受样品中无机离子及葡萄糖等非离子有机物的干扰。研究了离子交换法从苏氨酸等电母液中提取苏氨酸的方法。通过多种树脂对苏氨酸的离子交换吸附容量进行比较,选取001×7型强酸性阳离子交换树脂作为吸附树脂;通过静态吸附研究了吸附的动力学过程,同时考察了温度、pH、时间、氯化铵和氯化钠的浓度对离子交换树脂吸附苏氨酸的影响,表明吸附的适宜pH在4.5～5.8,氯化铵和氯化钠的存在均导致苏氨酸吸附速率迅速下降,温度对苏氨酸吸附影响不明显,吸附过程可在室温下进行。动态实验主要研究了离子交换柱对苏氨酸的吸附和洗脱过程,并在上柱液浓度、流量等因素的优化实验基础上设计了离子交换柱参数。选定氨水为洗脱剂,研究了氨水浓度和流量因素对洗脱效果的影响。结果表明:最佳吸附流量为5.72 SV;适宜的洗涤条件为:在水洗流速2.86SV时,水洗2.86BV;最佳洗脱条件为:洗脱流量为2.86SV,洗脱液氨水的浓度为1mol·L^-1,洗脱剂的合适用量为3.24BV;洗脱液中苏氨酸的浓度为76.27g·L^-1,苏氨酸的回收率为96.80%。用上述方法分离提取苏氨酸过程简单,对设备要求不高,生产成本低,适合大规模工业化生产的要求。更多还原

【Abstract】 Threonine is one of the eight necessary amino acids to human beings. It has wide applications in food, pharmatheutical and forage industry. It is very important of renewly making use of threonine mother liquor （that is to say, the supernatant of crysitilization of threonine） for there was about 7% threonine in it. In this paper, adsorption characteristics of threonine on ion exchange resin was studied and separation technics of threonine from threonine mother liquor was proposed.The method of quantitative determination of threonine were investigated. Nihydrin Colorimetry and Ion chromatography with conductivity detecto were compared, and ion chromatography with conductivity detector and C2 150/4.0 column were adopted. The eluents were tartaric acid ( 4.0 mmol·L^-1 )and 2, 6- Pyridinedicarboxylate (1.0 mmol·L^-1 )with isocratic eluting, and the flow rate was determined as 1.0 mL·min^-1. In this way, Amino acids can be determinated without precolumn derivation. The effect of inorganic cations and organic compounds on the determination of amino acids were studied. The results show that the excellent linear correlation coefficient（R） of threonine, valine, isoleucine and phenylalanine were achieved. The method can be used in the determination of amino acids in spite of the interferance of inorganic cations and organic compounds.The separation of threonine by ion exchange was studied. 001×7 ion exchange resin was selected as a suitable adsorptive material based on the study of ion exchange capacities. The kinetics behaviors of ion exchanging was studied by static adsorption experiments, and the influences of temperature, pH, time, concentrations of ammonia chloride and sodium chloride on threonine adsorption were investigated. The results indicated that the appropriate pH value was between 4.5 and 5.8 for adsorbing, the adsorption rates of threonine delined rapidly in the presence of ammonia chloride and sodium chloride, and temperature had little effect on adsorption of threonine.The dynamic adsorption process in ion exchange column was studied. Moreover, NH₃.H₂O was used as eluting solution in dynamic eluting process, and the influence of NH₃.H₂O concentration and the flow rate on elution were also investigated. The appropriate adsorption-desorption process was as follows: flow rate was 5.72 SV; wash out 2.86 BV at the wash rate of 2.86 SV; flow rate 2.86 SV in desorption with 3.24BV NH₃.H₂O solution of 1 mol·L^-1. the concentration of threonine was 76.27 g·L^-1. The recovery of threonine was 96.80%.Generally, the process for separation of threonine proposed is simple, and suitable for the industrial manufacture.更多还原