Chromatographic Separation of m-Cresol Purple and Its Impurity Profile

Description

m-Cresol Purple is an indicator dye commonly used in spectrophotometric pH measurements, particularly in oceanic CO₂ research. The purity of the dye is critical for ensuring accurate pH determination, as impurities can introduce significant uncertainty in the measurements.

Despite various attempts, purifying m-Cresol Purple has proven challenging due to either insufficient separation or low sample loadability on traditional HPLC columns. Using the Zodiac HST B2 mixed-mode column, a reliable method was developed that successfully separates four major impurities from the main compound, with excellent resolution.

m-Cresol Purple is a hydrophobic, acidic molecule, and both the parent compound and its impurities are retained and separated through a combination of reversed-phase and anion-exchange interactions on the Zodiac HST B2 column.

This method is particularly suitable for high-load preparative purification of acidic dyes, offering a robust solution for challenging separations in analytical and preparative-scale workflows.

Condition

1. MCP (m-Cresol Purple) Aldrich