Gradient Scouting in Reversed-Phase HPLC Revisited
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[1] Universidad de Sevilla
Universidad de Sevilla
Sevilla, España
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 88, Nº 1, 2011, págs. 74-76
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
Gradient scouting is the best way to decide the most suitable elution mode in reversed-phase high-performance liquid chromatography (RP-HPLC). A simple rule for this decision involves the evaluation of the ratio Δt/tG (where Δt is the difference in the retention time between the last and the first peak and tG is the time of the gradient), which is equated to a “magic” reference number. In this article, we demonstrate that the reference number depends on the cosolvent selected. This is illustrated with an example, using methanol as cosolvent. For methanol/water mobile phases, when Δt/tG < 0.15, an isocratic elution can be used, otherwise, gradient elution is advisable. In the example, a gradient elution was needed and a segmented gradient program was used to reduce the time of analysis. This article can serve as a reference and basis for laboratory experimentation in an upper-level analytical chemistry course.
