Simultaneous quantitative analysis of some main components in cinnamon leaves (Cinnamomum cassia) by HPLC-PDA

Cinnamon leaves, a part of the cinnamon tree, are used as raw materials to extract cinnamon essential oil and as a spice in food processing. Trans-cinnamaldehyde is the main ingredients that have biological effects and high concentration in cinnamon, cinnamic acid is often used as a marker in the quantification methods of cinnamon, coumarin is the ingredient that needs to be controlled due to risk of liver toxicity. So that, cinnamaldehyde (CAL), cinnamic acid (CA) and coumarin (CM) have been choosen to determin quality of cinnamon leaves. The analytes in the test sample were extracted with methanol:water ratio 9:1 by ultrasound twice 30 minutes and resting for 30 minutes between extractions. The ultrasonic extract was analyzed using an HPLC-PDA, C18 column (250×4.6 mm, 5 µm) at 25°C, mobile phase system consisting of acetonitrile and 0.05% phosphoric acid is eluted according to the program's gradient, detection wavelength 280 nm. The method was determined according to AOAC 2016 guidelines with appropriate specificity and linearity ranging from 51.90-691.31 µg/mL for coumarin, 1.00-20.10 µg/mL for cinnamic acid and 52.45-609.8 µg/mL for trans-cinnamaldehyde, good repeatability with RSD from 0.46% to 0.61%, accuracy of coumarin, cinnamic acid and cinnamaldehyd were 101.0%, 100.7% and 100.7% respectively, meets AOAC requirements at 3 concentration levels. The study applied quantitative research methods to quantify coumarin, cinnamic acid and transcinnamaldehyde on 17 C. cassia leaves samples collected in provinces in Vietnam. In result, analyte concentrations varied widely between samples, with coumarin ranging from 0.53- 2.47%, cinnamic acid from 0.01-0.08%, and cinnamaldehyde from 0.95-2.56%.