高效液相色谱法分析N-月桂酰基苏氨酸

Analysis of N-dodecanoyl Threonine by Using High-Performance Liquid Chromatography

采用两相滴定法对N-月桂酰基苏氨酸(C_(12)Thr)进行纯度分析时,发现有严重的乳化现象,对滴定终点判断产生明显干扰。为解决这一问题,建立了高效液相色谱法分析C_(12)Thr。采用示差折光检测器检测,以Hedera ODS-2 C18反相柱(250 mm×4.6 mm,5μm)为色谱柱、甲醇为流动相(流速为0.6 mL·min^(-1)),进样量为40μL,柱温35℃。结果表明:C_(12)Thr在质量浓度6.07×10^(-2)~1.62 g·L^(-1)范围内时,色谱流出曲线峰面积(A)与C_(12)Thr浓度(c,g·L^(-1))之间存在良好的线性关系:A=2.41×105 c+1.98×103(R2=0.9985),检测限为4.12×10^(-3) g·L^(-1),加标回收率为(99.55±0.18)%;同时,该分析条件对未反应的原料月桂酸(LA)也有很好的分析效果,LA和C_(12)Thr彼此间能够实现基线分离,LA浓度在6.49×10^(-3)~8.64×10^(-2) g·L^(-1)范围内存在良好的线性关系:A=2.14×105 c+4.43×102(R2=0.9993),检测限为4.32×10^(-3) g·L^(-1),加标回收率(99.47±0.16)%。

The purity of sodium N-dodecanoyl threonine(C_(12) Thr)was analyzed,and it is difficult to distinguish the titration end point due to emulsification.To solve this problem,a new method for determining C_(12) Thr by using high-performance liquid chromatography was established.Hedera ODS-2 C18 column(250 mm×4.6 mm,5μm)was used as the chromatographic column,the mobile phase was methanol(flow rate was 0.6 mL min^(-1)),the sample size was 40μL,the column temperature was 35℃and a refractive index detector was used.A good linear relationship between the concentration(c)and corresponding peak area(A)for C_(12) Thr in the range of 6.07×10^(-2)-1.62 limit was 4.12×10^(-3) g L^(-1).Meanwhile,this method could also detect the unreacted lauric acid(LA)and the baseline separation of LA from C_(12) Thr was achieved.In the LA concentration range of 6.49×10^(-3)-8.64×10^(-2) g L^(-1),a good linear equation of A=2.14×105 c+4.43×102(R2=0.9993)was obtained.The average recovery rate of LA was 99.47±0.16%with a detection limit of 4.32×10^(-3) g L^(-1).