Method Validation and Measurement Uncertainty Determination of Ethoxyquin and Antioxidant Activity in Paprika Seasonings and Paprika Sauces Frequently Consumed in South Korea

In this study, we investigated and validated a method for the quantitative analysis of ethoxyquin in paprika seasonings and sauces, which are frequently consumed in South Korea. Using this analytical method, we were able to confirm the presence of ethoxyquin under optimized high-performance liquid chromatography/photodiode array (HPLC-PDA) and liquid chromatography with tandem mass spectrometry conditions. Additionally, the antioxidant activity of ethoxyquin was assessed using the American Spice Trade Association values and its residual levels in paprika seasoning samples. The HPLC-PDA limits of detection and quantification for ethoxyquin were found to be 0.26 and 0.79 μg/mL, and 0.33 to 1.00 μg/mL, and the recoveries of ethoxyquin ranged from 86.75 to 101.70%, with relative standard deviations ranging from 0.31% to 3.59%. These results indicated that the analytical method in this study should be appropriate for the quantitative analysis of ethoxyquin in paprika seasoning and sauce matrices.