Neuberger Sabine, Jooß Kevin, Ressel Christian, Neusüß Christian
Faculty of Chemistry, Aalen University, Beethovenstraße 1, 73430, Aalen, Germany.
Anal Bioanal Chem. 2016 Dec;408(30):8701-8712. doi: 10.1007/s00216-016-9734-2. Epub 2016 Jul 12.
Capillary electrophoresis is commonly applied for the analysis of pharmaceutical products due to its high separation efficiency and selectivity. For this purpose, electrospray-ionization-(ESI)-interfering additives or electrolytes are often required, which complicates the identification of impurities and degradation products by mass spectrometry (MS). Here, a capillary zone electrophoresis (CZE) method with ultraviolet (UV) absorption detection for the simultaneous determination and quantification of ascorbic acid and acetylsalicylic acid in effervescent tablets was developed. Related degradation products were identified via CZE-CZE-MS. Systematic optimization yielded 100 mM tricine (pH = 8.8) as appropriate background electrolyte, resulting in baseline separation of ascorbic acid, acetylsalicylic acid, and related anionic UV-active degradation products. The CZE-UV method was successfully validated regarding the guidelines of the Food and Drug Administration. The validated method was applied to trace the degradation rate of the active pharmaceutical ingredients at defined ambient conditions. A heart-cut CZE-CZE-MS approach, including a 4-port-nL-valve, was performed for the identification of the observed degradation products. This 2D setup enables a precise cutting of accurate sample volumes (20 nL) and the independent operation of two physically separated CZE dimensions, which is especially beneficial regarding MS detection. Hence, the ESI-interfering tricine electrolyte components were separated from the analytes in a second electrophoretic dimension prior to ESI-MS detection. The degradation products were identified as salicylic acid and mono- and diacetylated ascorbic acid. This setup is expected to be generally applicable for the mass spectrometric characterization of CZE separated analytes in highly ESI-interfering electrolyte systems. Graphical Abstract A CZE-UV method for the quantification of effervescent tablet ingredients and degradation products was developed and validated. In order to identify unknown degradation products separated in the CZE-UV, a 2D heart-cut approach was performed applying a mechanical 4-port-valve. The unknown substances were transferred from the 1st to the 2nd dimension followed by the separation of ESI-interfering tricine from the analytes prior to mass spectrometric detection.
由于毛细管电泳具有高分离效率和选择性，因此常用于药品分析。为此，通常需要电喷雾电离（ESI）干扰添加剂或电解质，这使得通过质谱（MS）鉴定杂质和降解产物变得复杂。在此，开发了一种采用紫外（UV）吸收检测的毛细管区带电泳（CZE）方法，用于同时测定和定量泡腾片中的抗坏血酸和乙酰水杨酸。通过CZE-CZE-MS鉴定相关降解产物。系统优化得到100 mM三（羟甲基）甲基甘氨酸（pH = 8.8）作为合适的背景电解质，实现了抗坏血酸、乙酰水杨酸及相关阴离子型紫外活性降解产物的基线分离。CZE-UV方法已按照美国食品药品监督管理局的指导原则成功验证。经验证的方法用于追踪在规定环境条件下活性药物成分的降解速率。采用包括一个4端口纳升阀的中心切割CZE-CZE-MS方法来鉴定观察到的降解产物。这种二维设置能够精确切割准确的样品体积（20 nL），并实现两个物理分离的CZE维度的独立操作，这对于MS检测尤其有利。因此，在ESI-MS检测之前，在第二个电泳维度中将ESI干扰性三（羟甲基）甲基甘氨酸电解质成分与分析物分离。降解产物被鉴定为水杨酸以及单乙酰化和二乙酰化抗坏血酸。预计该设置通常适用于在高度ESI干扰的电解质系统中对CZE分离的分析物进行质谱表征。图形摘要 开发并验证了一种用于定量泡腾片成分和降解产物的CZE-UV方法。为了鉴定在CZE-UV中分离出的未知降解产物，采用机械4端口阀进行二维中心切割方法。未知物质从第一维度转移到第二维度，然后在质谱检测之前将ESI干扰性三（羟甲基）甲基甘氨酸与分析物分离。
