LC-MS法鉴定艾滋病治疗药物去羟肌苷的有关物质

目的：采用高效液相色谱-质谱联用技术鉴定艾滋病治疗药物去羟肌苷的有关物质结构。方法：InertSurstain C₁₈（250 mm×4.6 mm，5 μm）色谱柱，以0.386%醋酸铵溶液加氨水调节pH至8.0为流动相A，以甲醇-乙腈（50∶50）为流动相B，进行梯度洗脱，电喷雾正离子化高分辨TOF/MS和MS/MS检测并解析有关物质结构。TOF/MS雾化气压力345 kPa，温度350℃，干燥气流量10 L·min^-1，毛细管电压4 kV，碎片电压100 V，MS/MS测定氩气CID压力0.2 Pa，碰撞能量25 eV。结果：检测到去羟肌苷原料中共有8个有关物质，通过有机反应机制分析和质谱解析鉴定了他们的结构，他们分别是9-（2-氧基-丁酸）-1，4，5，7，8，9-六氢-嘌呤-6-酮、次黄嘌呤、肌苷、2'-去氧肌苷、9-（2-羟基-乙酰基）-1，9-双氢-嘌呤-6-酮、3'-去氧肌苷、2'，3'-脱水肌苷、9-（2-羟乙基-4-丙酸甲酯-四氢呋喃）-1，9-双氢-6H-嘌呤-6-酮。结论：采用色谱-质谱联用技术能有效地鉴定去羟肌苷的有关物质，可为其质量控制研究提供参考。

Objective: To identify the related substances of didanosine by hyphenated LC-MS methods.Methods: The separation was carried out on InertSurstain C₁₈(250 mm×4.6 mm, 5 μm) column with mobile phase consisting of 0.386% ammonium acetate solution(adjust pH=8.0 by amonia water solution) and methanol-acetonitrile(50:50) by gradient elution.The related substances were detected by positive ESI high resolution TOF/MS and their MS/MS spectra were determined as well.The conditions of TOF/MS were as follows:nebulizer pressure 345 kPa, gas temperature 350℃, drying gas flow 10 L·min^-1, capillary voltage 4 kV and fragmentor100 V.The argon collision gas pressure of MS/MS was set at 0.2 Pa, and the collision energy at 25 eV.Results: There were 8 related substances in didanosine and their chemical structures were determined through the elucidation of their accurate TOF/MS data, the corresponding product MS spectra and further validated with the organic reaction mechanisms.The impurities were identified as 9-(2-oxo-4-butiric acid)-1, 4, 5, 7, 8, 9-hexahydro-purin-6-amine, hypoxanthine, inosine, 2'-deoxyinosine, 9-(2-hydroxy-acetyl)-1, 9-dihydrogen-purin-6-amine, 3'-deoxyinosine, 2', 3'-anhydroinosine, 9-(2-ethoxy-4-methyl propionate-tetrahydrofuran)-1, 9-dihydrogen-6H-purin-6-amine.Conclusion: The LC-MS method is useful for the identification of related substances in pharmaceuticals.The related substances found in didanosine are valuable for its quality control.