A fast stop-flow two-dimensional liquid chromatography tandem mass spectrometry and its application in food-derived protein hydrolysates

Advances in separation and identification of biologically important milk proteins and peptides

“…The fast stop‐flow 2DLC‐MS in‐house constructed instrumentation has been used for peptide separation, identification, and search for bioactive peptides in various food‐derived protein hydrolysates including casein protein hydrolysates [121]. The combination of several types of chromatographic columns for coupling of SEC with RPLC was tested.…”

Two Multidimensional Chromatography/High-Resolution Mass Spectrometry Approaches Enabling the In-Depth Metabolite Characterization Simultaneously from Three Glycyrrhiza Species: Method Development, Comparison, and Integration

“…MDC can be operated in either the online or the offline mode, mainly including the applications of two-dimensional liquid chromatography (2D-LC) and three-dimensional liquid chromatography (3D-LC). , By MDC, the column combinations with large separation differences (referred to as high orthogonality) are often pursued. − Online 2D-LC has the merits of high automation, fast analysis speed, and good reproducibility, but it strongly depends on the availability of instruments . In contrast, the offline mode is highly accessible in the laboratories, flexible in integrating different mechanisms of separation, and free of the solvent effect, but often involves complex operations (e.g., eluate collection, solvent removal, and redissolution for sample injection). − In addition, 2D-LC can be divided into the comprehensive (LC × LC) and heart-cutting 2D-LC (HC-2D-LC) modes according to all of the one-dimensional fractions, or part of them are transferred and further separated by second-dimensional chromatography. , Comparatively, the comprehensive 2D-LC is advantageous in separating the complex components by feat of the greatly increased peak capacity and enhanced selectivity in separation, while HC-2D-LC selectively captures or enriches the target component(s), thus is more suitable for the quantitative assays. − Our recent research established two offline 3D-LC strategies by sequentially integrating ion exchange chromatography, hydrophilic interaction chromatography, and reversed-phase chromatography (IEC-HILIC-RPC) prior to the ultimate monitoring by high-resolution mass spectrometry (HRMS), which enabled the efficient discovery of numerous potential unknown structures.…”

“…16−18 Online 2D-LC has the merits of high automation, fast analysis speed, and good reproducibility, but it strongly depends on the availability of instruments. 19 In contrast, the offline mode is highly accessible in the laboratories, flexible in integrating different mechanisms of separation, and free of the solvent effect, but often involves complex operations (e.g., eluate collection, solvent removal, and redissolution for sample injection). 20−22 In addition, 2D-LC can be divided into the comprehensive (LC × LC) and heart-cutting 2D-LC (HC-2D-LC) modes according to all of the one-dimensional fractions, or part of them are transferred and further separated by second-dimensional chromatography.…”