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© 2021 MJH Life Sciences and Chromatography Online. All rights reserved.
© 2021 MJH Life Sciences™ and Chromatography Online. All rights reserved.
May 01, 2021
Dispersion of analyte peaks outside of chromatography columns can seriously erode the resolution provided by good columns. Here, we focus on the contribution of the sample injection step to the total level of extracolumn dispersion in an LC system.
April 07, 2021
Dispersion of analyte zones outside of the column often compromises the quality of an LC separation—particularly in smaller columns with smaller particles. We explain basic concepts in extra-column dispersion from the point of view of an entire instrument.
March 01, 2021
Liquid chromatography (LC) pumps produce mobile-phase streams with short-term variations in mobile-phase composition. We explain the impact of these waves on retention time in reversed-phase LC and what to do about it.
February 01, 2021
Liquid chromatography (LC) pumps produce mobile-phase streams with small short-term variations in mobile phase composition. We explain the origin of these variations and their effects on chromatographic performance.
January 01, 2021
Sometimes our approach to troubleshooting specific problems has to change in response to changes in high performance liquid chromatography (HPLC) technology over time. In this installment, we discuss changes in technologies for mobile-phase degassing, silica-based stationary phases, and models for reversed-phase selectivity.
December 01, 2020
Charged aerosol detection is a powerful complement to UV and MS, but successful implementation requires understanding a few key factors, including response dependencies on temperature, nebulization process, analyte volatility, and mobile-phase composition.
November 01, 2020
In 2D-LC, properties of the mobile phase used in first step can negatively affect the second step. We explain why this problem happens and how to avoid it.
September 01, 2020
A critical part of troubleshooting is understanding how the system should behave so that irregular behavior can be spotted. The more rules we know, the easier troubleshooting becomes. Learning these six rules is a great place to start.
August 01, 2020
If you are analyzing metal-sensitive biomolecules, and a bioinert instrument is unavailable, or insufficient, passivation or mobile-phase additives may help. Here’s how to use those solutions, with tips for avoiding potential pitfalls.
July 01, 2020
Taking a systematic approach to restarting liquid chromatography instrumentation following the COVID-19 shutdowns will save money and time in the long run.