Ghost peaks in reversed-phase gradient HPLC: a review and update

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Ghost peaks in reversed-phase gradient High-Performance Liquid Chromatography (HPLC) are a persistent challenge in analytical chemistry.
• Previous publications have documented various causes, but new sources continue to emerge, impacting data reliability.

Purpose of the Study:

• To describe new examples and sources of ghost peaks in reversed-phase gradient HPLC.
• To provide a broad perspective on ghost peak problems by relating new findings to existing literature.
• To offer practical recommendations for preventing ghost peaks.

Main Methods:

• Investigation of ghost peak occurrences in reversed-phase gradient HPLC systems.
• Analysis of solvent mixing and contamination as potential sources.
• Correlation of experimental observations with established HPLC principles.

Main Results:

• Identified ghost peaks resulting from intermittent non-delivery of the stronger solvent (solvent B) in stepped gradient elution.
• Discovered ghost peaks caused by plasticizer contamination in organic solvents.
• Documented specific scenarios leading to ghost peak formation.

Conclusions:

• Mixing problems and solvent contamination are significant contributors to ghost peaks in gradient HPLC.
• Implementing specific preventative measures can ensure consistent, ghost-peak-free HPLC analyses.
• Understanding these new sources aids in troubleshooting and optimizing HPLC methods.