The Gradient; Requirements, Optimal Use, Hints, and Pitfalls

Steiner, Frank

doi:10.1002/9783527694945.ch4

Cited by 3 publications

(1 citation statement)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A high-throughput LC method was able to reduce the gradient delay time to 1.8 s by reducing the system dwell volume, 81 but in general, LC separations on the subsecond time scale have been achieved using isocratic separations because of this delay volume as well as other issues related to column re-equilibration (see section on Two-Dimensional LC). 17,18 Fast gradients, and other rapid changes in pressure, can be detrimental to column lifetime, 82 which is another consideration when developing routine high-throughput methods.…”

Section: Considerationsmentioning

confidence: 99%

High-Throughput and Ultrafast Liquid Chromatography

et al. 2019

View full text Add to dashboard Cite

Section: Considerationsmentioning

confidence: 99%

High-Throughput and Ultrafast Liquid Chromatography

et al. 2019

View full text Add to dashboard Cite

Resolving power in liquid chromatography: A trade‐off between efficiency and analysis time

Dores-Sousa

Vos

Eeltink

2018

J of Separation Science

View full text Add to dashboard Cite

This review describes chromatographic dispersion and different plate‐height models frequently used to assess the chromatographic performance of ultra‐high‐pressure liquid chromatography column technology. Furthermore, different performance indices, including the resolution, the separation impedance, and kinetic plots are discussed allowing to quantify and visualize the resolving power in liquid chromatography. The construction of kinetic plots is explained, and different visualization approaches are highlighted. Finally, key instrument and column‐technology developments to advance the kinetic performance limits are discussed and selected state‐of‐the‐art applications are highlighted.

show abstract

Accuracy of retention model parameters obtained from retention data in liquid chromatography

Brau

Pirok

Rutan³

et al. 2022

J of Separation Science

View full text Add to dashboard Cite

In liquid chromatography, it is often very useful to have an accurate model of the retention factor, k, over a wide range of isocratic elution conditions. In principle, the parameters of a retention model can be obtained by fitting either isocratic or gradient retention factor data. However, in spite of many of our own attempts to accurately predict isocratic k values using retention models trained with gradient retention data, this has not worked in our hands. In the present study, we have used synthetic isocratic and gradient retention data for small molecules under reversed-phase liquid chromatography conditions. This allows us to discover challenges associated with predicting isocratic k values without the confounding influences of experimental issues that are difficult to model or eliminate. The results indicate that it is not currently possible to consistently predict isocratic retention factors for small molecules with accuracies better than 10%, even when using synthetic gradient retention data. Two distinct challenges in fitting gradient retention data were identified: 1) a lack of 'uniqueness' in the parameters and 2) an inability to find the global optimum fit in a complex fitting landscape. Working with experimental data where measurement noise is unavoidable will only make the accuracy worse.

show abstract

The Gradient; Requirements, Optimal Use, Hints, and Pitfalls

Cited by 3 publications

References 13 publications

High-Throughput and Ultrafast Liquid Chromatography

High-Throughput and Ultrafast Liquid Chromatography

Resolving power in liquid chromatography: A trade‐off between efficiency and analysis time

Accuracy of retention model parameters obtained from retention data in liquid chromatography

Contact Info

Product

Resources

About