In this research, a novel method was adopted for the extraction and determination of polyphenolic acids, i.e., chlorogenic acid, gallic acid, syringic acid and caffeic acid from different parts of Nepeta cataria L. samples. Extraction of polyphenolic acids from methanol extract was performed by ultrasound-assisted vesicles-based microextraction. In this procedure for the first time, 5-methyl salicylic acid was used for forming vesicles that trap analyte molecules in themselves. High-performance liquid chromatography was used for the separation and detection of polyphenolic acid content in Nepeta cataria L. samples. To obtain maximum extraction efficiency, some parameters affecting extraction efficiency were investigated and optimized. This analytical method was validated for linearity, precision, trueness, the limits of detection (LODs) and recovery. The LODs ranged from 0.3 to 0.9 ng mL‒1. Enrichment factors are between 102 and 116. Extraction recovery and relative standard deviation (RSD) values were calculated for both intraday and interday measurements. The extraction recovery and RSD values were in the concentration range of 84.2‒92.4% and 3.2‒4.6%, respectively. The method was successfully applied for the analysis of the collected real samples from Guilan, Golestan, Taleghan and Arak.
