LAUSR

In this study, we firstly employed response surface methodology to optimize the extraction conditions for separating diafenthiuron from fresh tea leaves via subcritical fluid extraction. Besides, the surface structure was characterized before and after the extraction. The results revealed that the experimental value was fitted to a second-order polynomial equation and the separation efficiency was estimated to be 92.89%, which is highly enough when applied in the industrial manufacture. Therefore, we performed subcritical fluid extraction experiments in the modified optimal conditions (i.e., 33 °C extraction temperature, 22 min extraction time, and 6.6:1 liquid-to-solid ratio) and measured a related value of 91.65%, consistent with the calculated result. Moreover, the surface structure of the tea leaves was intact after the extraction.