Coumarin is a phytotoxin found in the popular spice cinnamon, which is used to flavor many Asian curry dishes. In this work, we developed and compared the analytical performance of reversed-phase liquid chromatography (RP-LC) and sweeping-micellar electrokinetic chromatography (MEKC) methods for the determination of coumarin in complex curry (gravy) samples. Using a matrix matched sample (curry after solvent extraction with methanol and diluted with 100 mM phosphoric acid), the intra-day and inter-day repeatability of retention/migration time and (corrected) peak area for both methods were acceptable (%RSD (n=6) ≤ 5%). The linear range and limit of quantitation (LOQ) were an order of magnitude better in RP-LC (RP-LC linear range = 0.11-108 mg/kg, LOQ = 0.11 mg/kg) (Sweeping-MEKC linear range = 2.16-216 mg/kg, LOQ = 2.16 mg/kg). However, the limit of detection (S/N=3) and LOQ in sweeping-MEKC was 0.65 mg/kg and 2.16 mg/kg, which were sufficient to report the levels of coumarin ≥ the European limit of 2 mg/kg in foods. During the analysis of 25 curry samples, relatively similar results for sweeping-MEKC and RP-LC were obtained for 6 samples that contained coumarin >LOQ of sweeping-MEKC. Interferences in RP-LC lead to significant overestimation of coumarin levels in 3 samples. Coumarin levels above the EU limit was found in 6 curry samples using the more selective sweeping-MEKC. This work should also raise public awareness on the presence of potentially high levels of coumarin in some foods.

Item Type:	Refereed Article
Keywords:	Cinnamon, Coumarin, Curry, Micellar electrokinetic chromatography, Reversed-phase liquid chromatography, Solvent extraction
Research Division:	Chemical Sciences
Research Group:	Analytical chemistry
Research Field:	Separation science
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the chemical sciences
UTAS Author:	Ranasinghe, M (Mrs Muhandiramge Ranasinghe)
UTAS Author:	Quirino, JP (Associate Professor Lito Quirino)
ID Code:	151658
Year Published:	2021
Web of Science® Times Cited:	4
Deposited By:	Chemistry
Deposited On:	2022-08-02
Last Modified:	2022-09-06
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