目的 采用高效液相色谱法和电位滴定法建立草酸艾司西酞普兰有关物质检查及含量测定的方法，为原料药的质量控制提供有效的分析方法。 方法 采用 Inertsil C₁₈(4.6 mm×250 mm，5 μm)色谱柱，流动相为乙腈-醋酸盐缓冲液(取1 g醋酸钠，溶解于800 mL水中，加入6 mL三乙胺，用冰醋酸调pH值至5.0，加水至1 000 mL)( 30∶70);流速:1.0 mL· min^-1;检测波长:239 nm;柱温:40 ℃;电位滴定法以冰醋酸为溶剂，高氯酸滴定液(0.1 mol·L^-1)滴定。结果 在选定的色谱条件下，草酸艾司西酞普兰与8种有关物质分离完全;草酸艾司西酞普兰的线性范围为10~800 μg· mL^-1，相关系数r为0.999 9;检测限为0.94 ng;日内精密度和日间精密度的RSD值分别为0.39%(n=6)和0.77%(n=5);各杂质的线性范围为0.1~10 μg· mL^-1，相关系数r≥0.999 9;电位滴定突跃明显，精密度RSD值为0.1%(n=6)。结论 方法简便、准确、专属性强，可用于草酸艾司西酞普兰有关物质检查及含量测定。

OBJECTIVE To establish an HPLC method and potentiometric titration method for the determination of escitalopram oxalate and its related substances for quality control. METHODS Chromatography was carried out on an Inertsil C₈ column (4.6 mm×250 mm,5 μm), using the mobile phase of acetonitrile-acetate buffer solution (containing 1 g sodium acetate and 6 mL triethylamine in 1 000 mL of water, pH adjusted to 4.6 with acetic acid ) (30∶70) at the flow rate of 1.0 mL·min^-1. The detection was carried out with a UV detector at 239 nm, and the column temperature was 40 ℃. The determination was also performed by potentiometric titration, using glacial acetic acid as solvent and 0.1 mol·L^-1 perchloric acid as titrant. RESULTS Escitalopram oxalate and the related substances were separated completely under the above chromatographic conditions. The standard curve of escitalopram oxalate was linear within the range of 10-800 μg·mL^-1, with the correlation coefficient of 0.999 9, and limit of detection of 0.94 ng. The intra-day and inter-day RSDs were 0.39%(n=6) and 0.77%(n=5), respectivley. The calibration curves of impurities were linear over 0.1-10 μg·mL^-1 (r≥0.999 9). There was obvious on titration process, and the RSD for precision was 0.1%(n=6). CONCLUSION The established methods are simple, accurate, specific and can be used for quality control of escitalopram oxalate.