qNMR as an analytical technique for essential oils: quantitative analysis of Eucalyptus tereticornis leaf oil

Eucalyptus (Myrtaceae) is a genus of extremely varied blooming trees that produce valuable essential oil as well as hard and durable heartwood. The primary sources of eucalyptus oil are the leaves of Eucalyptus globulus, E. citriodora, E. tereticornis. The essential oil is isolated by hydro-distillation and is used as a medication, antibacterial, repellent, flavouring agent and in aromatherapy. Monoterpenes like 1,8-cineole, α-pinene, β-pinene and limonene are the major components of the oil. The present study was planned to do the quantitative analysis of essential oil in Eucalyptus tereticornis leaves by qNMR as an alternate analytical technique in addition to more commonly used GC–MS. The method was validated with respect to selectivity, linearity, accuracy, precision and robustness. The developed method can be used to analyse Eucalyptus oil from diverse species as they also contain these volatiles but in different ratios.