Cinnamon essential oil is commonly used in daily life, production, and health. This study introduces a straightforward, reliable, and highly accessible HPLC method for the quality assessment of cinnamon essential oil. Three selected markers: trans-cinnamaldehyde, cinnamic acid, as the main components, are used as components in the process of quantifying cinnamon components, and coumarin is of interest due to concerns about the risk of liver toxicity. These three components are assayed in cinnamon bark and leaves, the raw materials for distilling cinnamon essential oil. The sample was diluted with a 7:3 methanol:water ratio, analyzed by HPLC-DAD using Phenomenex Gemini C18 column (250 × 4.6 mm, 5 µm), a gradient mobile phase program consisting of acetonitrile and 0.05% phosphoric acid, and a detection wavelength of 280 nm. The validated method had suitable specificity, a linear range from 0.51 to 385.16 µg/mL for coumarin, 0.48–199.60 µg/mL for cinnamic acid, and 38.18–458.16 µg/mL for trans-cinnamaldehyde, good repeatability with RSD from 0.7-1.1%, and the precision of coumarin, cinnamic acid, and trans-cinnamaldehyde were 100.3%, 98.8%, and 100.5%, respectively, meeting the requirements of AOAC. This method was used to quantify seventeen cinnamon essential oil samples, including essential oil from leaves and bark of Cinnamomum cassia, commercial samples, and smallholders’ products.
Ngo et al. (Wed,) studied this question.