Single-laboratory validation of a quantification method for quercetin and kaempferol aglycones in radish (Raphanus sativus L.) leaves

Abstract

This study developed and validated a quantification method for quercetin and kaempferol aglycones in radish leaves, following the Association of Official Analytical Chemists (AOAC) guidelines for single-laboratory validation. Among various hydrolysis conditions tested, heating at 90 °C for 30 min without ascorbic acid yielded the highest analytical values. The developed method satisfied AOAC requirements for repeatability precision, and accuracy. Additionally, robustness testing using the Plackett-Burman design identified hydrolysis temperature as a significant factor influencing analytical results. The method was subsequently applied to compare quercetin and kaempferol content in five radish leaf varieties cultivated during different periods. Seasonal variations in both the content and ratio of these compounds were observed.