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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 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]

The article focuses on the "kinetic plot", a powerful graphical tool that can help leverage the best available theory to help us understand how different combinations of parameters and therefore make well-informed decisions when choosing columns.

With the introduction of ultrahigh pressure and performance instrumentation and sub-2-µm superficially porous particles (SPPs), a gigantic leap in separation performance was achieved starting approximately 20 years ago. Although smaller advances have been made in the past decades, the question remains whether further extending operating pressure and decreasing particle size remains a feasible approach, or whether drastically novel approaches are required. [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 installment, we focus on the contributions of dispersion in connecting tubing and detectors to the total level of extracolumn dispersion in a 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 installment, 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 installment, we focus on basic concepts in extracolumn dispersion as a prelude to future installments that will focus on dispersion in specific elements of HPLC systems. [ABSTRACT FROM AUTHOR]

This installment is the first of a series of four white papers on high performance liquid chromatography (HPLC) modules (pump, autosampler, ultraviolet [UV] detector, and chromatography data system [CDS]) to be published in 2019. This installment 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 discusses the advantages in pressure controlled elution of chromatographic analytes in liquid chromatography over traditional approach of constant rate of elution. It mentions that the application of constant pressure to the chromatographic column for elution reduces the analysis time required in chromatographic analysis. It highlights that pressure controlled elution of samples is the most specific and sensitive approach for elution of chemical samples.

Dispersion (broadening, or spreading) of analyte zones (peaks) outside of chromatography columns can seriously erode the resolution provided by good columns. In this installment, we focus on the impact of elution mode (isocratic or gradient) and post-column 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]