Simple and comprehensive two-dimensional reversed-phase HPLC using monolithic silica columns.

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Two-dimensional High-Performance Liquid Chromatography (2D-HPLC) is a powerful technique for separating complex mixtures.
• Monolithic silica columns offer high efficiency and stability, making them suitable for advanced chromatographic applications.

Purpose of the Study:

• To investigate the application of monolithic silica columns in both dimensions of a 2D-HPLC system.
• To evaluate different configurations of 2D-HPLC for achieving simple and comprehensive separations.
• To assess the separation performance, including peak capacity and time, of the developed 2D-HPLC methods.

Main Methods:

• Utilized reversed-phase mode with monolithic silica columns for the second dimension (2nd-D) separation.
• Employed fluoroalkylsilyl-bonded (FR) silica particles in the first dimension (1st-D) column.
• Investigated three distinct 2D-HPLC configurations, including direct loading, valve-based comprehensive 2D-HPLC, and dual-column 2nd-D systems.
• Tested stationary phases: FR, octadecylsilylated (C(18)), and (pentabromobenzyloxy)propylsilyl-bonded (PBB).

Main Results:

• Achieved a peak capacity of approximately 1000 within 60 minutes for simple and comprehensive 2D-HPLC systems.
• Demonstrated separation times of approximately 30 minutes in a dual-column 2nd-D setup.
• Showcased widely different selectivities among FR, C(18), and PBB stationary phases, enabling effective 2D separations.
• Monolithic silica columns facilitated high efficiency at high linear velocities.

Conclusions:

• Simple and comprehensive 2D-HPLC using monolithic silica columns is a viable and efficient technique.
• The investigated configurations offer flexibility in optimizing separation for complex samples.
• The stability and high efficiency of monolithic silica columns are key advantages for advanced 2D-HPLC applications.