ABSTRACT
High-performance liquid chromatography (HPLC) represents a powerful method widely applied for the separation of real-world samples in several elds. Although this methodology may often provide sufcient resolving power for the separation of target components, many matrices present a complexity that greatly exceeds the separation capacity of any single chromatographic system. Therefore, despite a careful method optimization procedure, conventional HPLC may be inadequate when faced with truly complex samples. Moreover, peak overlapping may occur even in the case of relatively simple samples that contain components with similar properties. In such cases, the combination of more than one separation step is a convenient choice, generating a great increase in the resolving power of a chromatographic system, expanding separation space, enhancing peak capacity, and, thus, enabling the resolution of components even in highly complex matrices.
