Determination of dyes and marker in diesel using high performance liquid chromatography

A fast, precise and accurate high performance liquid chromatography method has been developed for the determination of dyes (Solvent Red 19 and Solvent Blue 35) and a marker (Solvent Yellow 124) in diesel. Separation was carried out on a 250 x 4.60 mm Agilent Zorbax Rx-SIL column (5 mu m particle size). Detection was done in a visible wavelength range. The best performance of fuel dye separation and the shortest retention times were achieved when using hexane, toluene and ethyl acetate as a mobile phase. During this research the eluent composition and the elution gradient were optimized consequently that helped to perform the analysis within 15 min. The developed method was applied for the analysis of real samples of dyed diesel fuel. Preparation of the samples for the analysis simply consisted of filtering through a 0.45 mu m filter previous to direct injection of the sample into the HPLC system for analysis.