为了定量测定依卡倍特钠中潜在遗传毒性杂质依卡倍特磺酸乙酯（杂质Ⅰ）,参考文献方法合成依卡倍特磺酸乙酯。采用高分辨质谱、结合二级质谱与核磁共振确定其相对分子质量及化学结构。采用Thermo C18色谱柱,以5 mmol/L乙酸铵溶液（甲酸调p H至3.0）为流动相A;乙腈为流动相B,按照梯度：0 min 50%B,4 min 50%B,12 min 80%B,16 min 80%B,16.1 min 50%B,20 min 50%B进行洗脱,柱温40℃;采用电喷雾负离子化-MS/MS选择反应监测。杂质Ⅰ的线性质量浓度范围为4-150 ng/m L,且线性关系良好（r=0.999）;最低定量限为4 ng/m L;杂质Ⅰ的进样精密度、重复性和加标回收率良好,耐用性良好。方法操作简便,灵敏度高,可用于依卡倍特钠原料药中潜在遗传毒性杂质依卡倍特磺酸乙酯的含量测定。
To develop a sensitive analytical method for the determination of the genotoxic impurity mono ethyl ester of ecabet（ Imp-I）,an HPLC-MS/MS technique was employed. Imp-I was synthesized according to the previous literatures. MS/MS and NMR were used to confirm the structure of Imp-I. A Thermo C18 column was used for chromatographic separations. The mobile phase consisting of A： 5 mmol/L ammonium acetate（ p H adjusted to 3. 0 with formic acid） and B： acetonitrile,with a gradient program： 0 min 50% B,4 min 50% B,12 min 80% B,16 min80% B,16. 1 min 50% B and 20 min 50% B. The column was maintained at 40 ℃ throughout the analysis. All measurements were carried out with the mass spectrometer operated under the negative ESI mode. The selective reaction monitor（ SRM） transition was used. Good linearity was obtained for Imp-I over the concentration range of4-150 ng/m L with the coefficient of determination（ r） of 0. 999. And the LOQ was 4 ng/m L. A rapid and sensitive HPLC-ESI-MS/MS method was developed for quantitative analysis of Imp-I in ecabet sodium APIs. This method can be of used for quality assurance of ecabet sodium in bulk commercial drugs.
Journal of China Pharmaceutical University