Comprehensive on-line two-dimensional liquid chromatography (LCxLC) is expected to generate impressive peak capacities, which makes it a method of choice for the analysis of complex samples such as pharmaceuticals. A comparative study of different sets of chromatographic conditions including stationary phase, pH additive and organic modifier was carried out with two real pharmaceutical samples in order to find out the best analytical conditions for implementation of one or several generic on-line LCxLC separations. Our choice was based on the evaluation of both degree of orthogonality and practical sample peak capacity under linear gradient conditions. The potential of 190 combinations of chromatographic systems was compared. A set of 3 RPLCxRPLC configurations was found to be very attractive for both samples and in good agreement with the findings of a previous study carried out with 17 model compounds, thereby supporting the idea of using generic LCxLC conditions in the pharmaceutical area. The three selected 2D-systems were implemented for the on-line RPLCxRPLC-UV/MS analysis of two pharmaceutical samples. It was shown, for each sample, that these 2D-systems were able to generate an effective peak capacity close to 1000 in less than 50 min. For each sample, baseline separation was obtained for every known compound and furthermore a large number of unknown impurities could also be separated and identified. Finally, in the proposed conditions, the total number of compounds detected was significantly improved from one RPLC separation to one RPLCxRPLC separation. Only a small additional gain was observed by performing a second RPLCxRPLC separation or even a third one.

全面的在线二维液相色谱（LCxLC）有望产生令人印象深刻的峰容量，这使其成为分析复杂样品（如药物）的一种选择方法。为了研究实现一种或几种通用在线LCxLC分离的最佳分析条件，对两个固定药物样品进行了包括固定相，pH添加剂和有机改性剂在内的不同色谱条件的比较研究。我们的选择基于线性梯度条件下正交度和实际样品峰容量的评估。比较了190种色谱系统组合的潜力。发现一套3种RPLCxRPLC配置对两个样品都非常有吸引力，并且与先前对17种模型化合物进行的研究结果十分吻合，从而支持了在制药领域使用通用LCxLC条件的想法。实施了三个选定的2D系统，用于对两个药物样品进行在线RPLCxRPLC-UV / MS分析。对于每个样品，这些二维系统都能够在不到50分钟的时间内产生接近1000的有效峰容量。对于每个样品，每种已知化合物均获得了基线分离，此外，还可以分离和鉴定大量未知杂质。最后，在建议的条件下，从一次RPLC分离到一次RPLCxRPLC分离，检测到的化合物总数得到了显着改善。