Simultaneous quantification of chlorogenic acid, quercetin, and kaempferol in leaves by CE and HPLC techniques: method validation and comparative study.

Two analytical methods, CE and HPLC, were developed, validated, and compared for simultaneously determining chlorogenic acid, quercetin, and kaempferol in leaves collected from twelve different sources of Thailand. The determination was accomplished by CE on the uncoated fused silica capillary tube and by HPLC on the ZORBAX Eclipse Plus C18 column. Chlorogenic acid was found to have the highest average amount in leaves, followed by kaempferol and quercetin, respectively. Compared to CE, HPLC is considered to provide higher sensitivity and robustness as indicated by lower LOD and LOQ values as well as % RSD of robustness for all analytes. Overall, the present study first demonstrated that both methods were selective, sensitive, and robust, allowing reliable simultaneous quantification of three major bioactive compounds in leaves, which could be beneficially applied for quality control assessment of this plant material, particularly those cultivated in Thailand.