流动注射抑制化学发光法测定阿魏酸

基于阿魏酸对鲁米诺-铁氰化钾化学发光体系的抑制作用,建立了阿魏酸的流动注射抑制化学发光分析法,在优化的实验条件下,阿魏酸浓度在4.0×10~(-7)～4.0×10~(-6) mol/L之间时,与化学发光强度减小值呈现良好线性关系,检出限为2.4×10~(-7) mol/L,对1.0×10~(-6) mol/L阿魏酸的相对标准偏差为1.4%(n=9),将其应用于复方当归注射液中阿魏酸含量的测定,结果令人满意.此外,结合化学发光光谱和紫外吸收光谱对抑制化学发光机理进行了初步探讨.

Abstract：

Based on the fact that the chemiluminescence intensity of the luminol- K3Fe(CN)6 system is inhibited in the presence of ferulic acid, a novel flow injection chemiluminescence inhibition method for the determination of ferulic acid was developed. Under the optimum conditions, the decrease in chemiluminescence intensity was linear with ferulic acid concentration in the range from 4. 0 × 10~(-7) to 4.0 × 10~(-6) mol/L.The detection limit was 2.4 × 10~(-7) mol/L and the relative standard deviation was 1.4% for 1.0 × 10~(-6) mol/L ferulic acid (n=9). When applied to the determination of ferulic acid in Fufang Danggui Injection samples, this method gave satisfactory results. Furthermore, combining the chemiluminescence spectra with the UV absorption spectra, the paper presents a brief discussion of their chemiluminescence inhibition mechanisms.     

双官能团离子液体[Promim]^＋[CF3CO2]^-支撑不对称Aldol反应的密度泛函理论研究

用密度泛函理论B3LYP方法对双官能团离子液体[Promim]+[CF3CO2]-支撑丙酮与邻-硝基苯甲醛不对称aldol反应进行了研究.结果表明,该离子液体的脯胺酸和咪唑基团一起对反应产生催化作用.整个反应包括:丙酮的羰基与脯胺酸基团的胺基间的亲核加成反应,咪唑2-位氢参与的脱水反应生成亚胺IM1-2,丙酮甲基脱氢反应生成烯胺I M1-3,苯甲醛与烯胺的亲核加成反应,水加成反应和催化剂再生反应.第一步骤是速率控制步骤,产物羟基位碳原子的手性在苯甲醛与烯胺的亲核加成反应中产生.另外,在咪唑环2-位氢参与的脱水反应中生成的水分子辅助丙酮甲基脱去α-氢生成烯胺.苯甲醛邻位吸电子基团能降低醛基碳原子的电子密度,增强醛基碳原子的亲电性,从而增强反应物活性.离子液体[Promi m]+[CF3CO2]-产生的溶剂化效应使反应势垒降低(除开催化剂再生步骤).