原子转移自由基聚合技术制备新型手性配体交换色谱固定相及对手性化合物的拆分  

Preparation of Chiral Ligand Exchange Chromatographic Stationary Phase by Atom Transfer Radical Polymerization for Separation of Racemates

作　　者：孙杨[1] 张雷[1] 徐飞[1] 龚波林[1] 

机构地区：[1]宁夏大学能源化工重点实验室,宁夏天然产物工程技术研究中心,银川750021

出　　处：《高等学校化学学报》2012年第12期2644-2650,共7页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:201065008);国家科技部重大基础研究前期研究专项(批准号:2009CB626608)资助

摘　　要：采用原子转移自由基聚合(ATRP)技术,以溴代硅胶为引发剂,CuCl/2,2'-联吡啶(Bpy)为催化体系,水为溶剂,N-丙烯酰基-L-脯氨酸为单体,室温下在硅胶表面进行聚合反应,制得硅胶接枝聚N-丙烯酰基-L-脯氨酸分子刷.通过改变ATRP反应体系中单体的量,制备了3种不同键合量且键合量可控的手性配体交换色谱固定相,利用元素分析和热重分析对其进行表征.考察了配体接枝率、流动相Cu2+浓度、pH值和柱温等对DL-氨基酸和α-羟基酸拆分的影响,优化了色谱分离条件,探讨了拆分过程的热力学.结果表明,所合成的手性配体交换色谱固定相能够分离9种DL-氨基酸和α-羟基酸,其中DL-酪氨酸、DL-色氨酸和DL-苏氨酸3种氨基酸可同时进行拆分,且拆分过程由熵控制.A novel stationary phase was synthesized for chiral ligand exchange chromatography （CLEC） via atom transfer radical polymerization （ATRP） method. Poly （ 1-acryloylpyrrolidine-2-carboxylic acid） polymer brush was grafted onto the surface of the silica by ATRP using 2-bromoisobutyryl bromide as an initiator, and the organic metal compound formed in the CuCl/2,2′-bipyridine（Bpy） system as a catalyst in water medium at room temperature. Three high-capacity chiral stationary phases obtained with different ATRP formulations were tried as chromatographic packings in CLEC. The stationary phases were characterized by means of elementary analysis and thermogravimetric analysis. The influence of the ligand grafted-density, mobile phase pH, concentration of Cu^2＋, temperature of column on the resolution of DL-amino acids by CLEC were investigated, and the optimized chromatographic conditions were selected. The thermodynamics for separatins of racemates was discussed. The results showed that the prepared columns could separate nine DL-amino acids and α-hydroxy acid with high separation factor, and high retentions. The DL-threonine, DL-tyrosine and DL-tryptophan could be simultaneously separated using the stationary phase. It could be proved that the entropy controlled the process of chiral separation.

关 键 词：原子转移自由基聚合 手性配体交换色谱 对映体分离 DL-氨基酸 Α-羟基酸 

分 类 号：O657[理学—分析化学]