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Choosing a liquid chromatography (LC) column for a particular application can be a surprisingly challenging task. On one hand, column manufacturers give us many options to choose from, including particle types, pore sizes, particle sizes, and different lengths and diameters. On the other hand, we usually don't have time to experimentally evaluate many combinations of these parameters, and sometimes we end up picking something similar to the columns that are already in the drawer. The "kinetic plot" is a powerful graphical tool that can help leverage the best available theory to help us understand how different combinations of parameters (that is, particle size and length) will perform in terms of the time needed to get to a particular column efficiency (and thus resolution), and therefore make well-informed decisions when choosing columns. [ABSTRACT FROM AUTHOR]

Choosing a liquid chromatography (LC) column for a particular application can be a surprisingly challenging task. On the one hand, column manufacturers provide us with many options to choose from, including particle types, pore sizes, particle sizes, and different lengths and diameters. On the other hand, we usually do not have time to experimentally evaluate many combinations of these parameters, and sometimes we end up picking something similar to the columns that are already available. The "kinetic plot" is a powerful graphical tool that can help leverage the best available theory to help us understand how different combinations of parameters (that is, particle size, length, among others) will perform in regard to the time needed to get to a particular column efficiency (and thus resolution), and therefore make well-informed decisions when choosing columns. [ABSTRACT FROM AUTHOR]

Choosing a liquid chromatography (LC) column for a particular application can be a surprisingly challenging task. On the one hand, column manufacturers give us many options to choose from, including particle types, pore sizes, particle sizes, and different lengths and diameters. On the other hand, we usually do not have time to experimentally evaluate many combinations of these parameters, and sometimes we end up picking something similar to the columns that are already in the drawer. The "kinetic plot" is a powerful graphical tool that can help leverage the best available theory to help us understand how different combinations of parameters (such as particle size and length) will perform in relation to the time needed to get to a particular column efficiency (and thus resolution), and therefore make well-informed decisions when choosing columns. [ABSTRACT FROM AUTHOR]

Dispersion (broadening, or spreading) of analyte zones (peaks) outside of chromatography columns can seriously erode the resolution provided by good columns. In this final instalment of the series we focus on the impact of elution mode (isocratic or gradient) and postcolumn flow splitting on the total level of extracolumn dispersion (ECD) in a liquid chromatography (LC) system, and demonstrate the use of a free, web-based calculator that can be used to guide decision making aimed at reducing ECD during method development. [ABSTRACT FROM AUTHOR]

Dispersion (broadening, or spreading) of analyte zones (peaks) outside of chromatography columns can seriously erode the resolution that good columns provide. In this instalment, we focus on the contributions of dispersion in connecting tubing and detectors to the total level of extracolumn dispersion in a liquid chromatography (LC) system. [ABSTRACT FROM AUTHOR]

Dispersion (broadening, or spreading) of analyte zones (peaks) outside of chromatography columns can seriously erode the resolution provided by good columns. In this instalment, we focus on the contribution of the sample injection step to the total level of extracolumn dispersion in a liquid chromatography (LC) system. This contribution has both a physical component (that is impacted by injector design and configuration and method variables) and a chemical component (that depends on the difference between the mobile phase and the sample solvent compositions). [ABSTRACT FROM AUTHOR]

Dispersion (the broadening or spreading) of analyte zones (peaks) outside of chromatography columns can seriously erode the resolution provided by good columns. Understanding the relationship between the level of dispersion associated with a given instrument relative to the intrinsic efficiency of a given column can help avoid disappointing results, especially when switching to new column technologies. In this instalment, we focus on basic concepts in extracolumn dispersion as a prelude to future instalments that will focus on dispersion in specific elements of high performance liquid chromatography (HPLC) systems. [ABSTRACT FROM AUTHOR]

This instalment is the first of a series of four white papers on high performance liquid chromatography (HPLC) modules (pump, autosampler, UV detector, and chromatography data system) to be published in 2019. This instalment provides an overview for analytical-scale HPLC pumps, including their requirements, modern designs, operating principles, trends, and best practices for trouble-free operation. [ABSTRACT FROM AUTHOR]

The article focuses on the development in the liquid chromatography instruments with the introduction of fully porous particles rather than the old columns. It discusses how the ultra high-performance liquid chromatography (UHPLC) should be improved with separation quality and operating pressure, and analyze the separation performance while applying kinetic plot methodology.

The article offers information on a study on the comparison of the separation speed of gas chromatography (GC), liquid chromatography (LC), and supercritical fluid chromatography (SFC). Topics discussed include using the kinetic plot method neglecting differences in viscous heating or extra-column band broadening; obtaining fixed length kinetic plot curves; and role of thermodynamic resistance factor in LC.

The throughput of a laboratory can be optimized by selecting the optimum particle diameter and column length for a specific stationary phase. This selection can be made using a step-by-step method based on the recently established kinetic plot method for gradient separations. An example involving the separation of environmental pollutants demonstrates how this approach worked in practice. [ABSTRACT FROM AUTHOR]