Efficient separation and quantification of methyl palmitate and methyl oleate in biodiesel mixture using reverse-phase high performance liquid chromatography

ABSTRACT The excessive utilization of petroleum resources leads to global warming, crude oil price fluctuations, and fast depletion of petroleum reserves. Biodiesel (Fatty Acid Methyl Ester, FAME) has gained importance as a clean and renewable energy source over the last few years. It is produced by reacting vegetable oils and short-chain alcohols via transesterification/esterification reaction. The properties of biodiesel depend on the vegetable oils’ fatty acid composition due to the saturated and unsaturated fatty acid content variation. During the FAME quantification analysis, separation of methyl palmitate (MeP) and methyl oleate (MeO) are major challenges in the C18 column in High Performance Liquid Chromatography (HPLC). These components are difficult to quantify as they elute simultaneously by forming an overlapping peak. A new reverse-phase HPLC separation method with C18 column has been developed to efficiently separate and quantify FAMEs derived from palm oil. UV-VIS detector was used at 205 nm. The FAMEs separation was achieved using ternary mobile phase solvents acetonitrile, water, and acetone with the composition of 62%, 33%, and 5% in an isocratic flow with 2.20 mL/min flowrate and 45 °C column temperature. Methyl esters were analyzed with satisfactory linearity (r 2 >0.99), repeatability (relative standard deviation <2%), and sensitivity (limit of quantification). GRAPHICAL ABSTRACT