柱前衍生化高效液相色谱法准确测定2-氯丙酸的光学纯度

Accurate Measurement of Optical Purity of 2-Chloropropionic Acid by Precolumn Derivatization-High Performance Liquid Chromatography and Its Application

用1-萘胺对2-氯丙酸进行柱前衍生化,衍生化反应在30℃条件下进行10min或更长时间。选择ChiralcelOD-H色谱柱和正己烷-醇类为流动相,考察了流动相组成和柱温的变化对2-氯丙酸衍生物对映体拆分效果的影响。确定流动相为V(正己烷):V(甲醇):V(乙醇)=50:45:5,流速1.0mL/min,柱温30℃,检测波长224nm为较优分析条件,分离因子2.5,8min内出峰。现有文献和试剂手册提供的2-氯丙酸的比旋光度标准值之间相差很大,在实际测量和计算中无准确标准可依。柱前衍生化结合手性固定相色谱方法灵敏度高,重现性好,操作较简单,可用于准确测量2-氯丙酸的光学纯度,并准确给出一定条件下2-氯丙酸的比旋光度和光学纯度的对应关系([α]D20-13.94(neat,d1.2547),e.e.97.9%)。

2-Chloropropionic acid was preliminarily derivatized with 1-naphthylamine at 30℃ for 10 minutes, and then could be satisfactorily separated in 8 min by Chiralcel OD-H column and hexane-alcohol eluent. The effects of composition of mobile phase and column temperature on the chiral separation were investigated. The optimal analysis conditions were obtained as： mobile phase, hexane-methanol-ethanol （50：45：5, V/V） ; flow rate, 1.0 mL/min; temperature, 30℃; wavelength, 224 nm. More accurate standard specific rotation of 2-chloropropionic acid and relative e.e valuse are [α]^200-13.94（neat, dl. 2547） and e. e. 97.9%. This method is proved to be sensitive, easy for operation and good for accurate optical purity measurement of 2-chloropropionic acid.