Quality Assurance of Petrol by HPLC

Abstract

A simple and rapid reverse phase HPLC method has been developed for the determination of adulteration in petrol (gasoline) with Kerosene. Methanolic solutions of petrol, Kerosene and their synthetic admixtures were analysed on HPLC using C₁₈ ODS column and Acetonitrile : Water (8:2) as mobile phase, at the flow rate of 1 ml/min and UV-absorption detection at 285 nm. The UV detector at 285 nm gives specificity to detection, since the alkyl naphthalenes predominantly present in kerosene have strong, characteristic absorption around 285 nm. The amplitudes of the peaks corresponding to these naphthalenes (C-10–C-12) increased with the added quantum of kerosene linearly. Average values with ± SD of intrachromatographic ratios generated for the peak heights of the naphthalenes Σ(C-10 to C-12) divided by peak height of solvent methanol were tabulated. These ratios could be used to get a linear curve if evaluated graphically against corresponding (P:K) composition for determining extent of adulteration with kerosene, even down to a level of 5% v/v in suspected petrol samples.