Air assisted - vesicle based microextraction (AAVME) as a fast and green method for the extraction and determination of phenolic compounds in M. officinalis L samples

In this research, a simple, rapid, and efficient air assisted - vesicle based microextraction (AAVME) approach was developed for the extraction of phenolic compounds and their analysis in different Melissa officinalis L. samples. The extraction method is based injection an aqueous mixture of CTAB and 5-methyl salicylic acid, into the hydroalcoholic plant extract in a conical test tube to form a cloudy solution. Suction and dispersion were then applied to accelerate the dispersion process. After centrifugation, the sediment phase was removed and injected into HPLC system. The optimized extraction conditions were as 450 μL of a mixture of CTAB and 5-methyl salicylic acid (3:5 mol ratios), 10.0 mL sample solution at pH 8.0 and 30 suction-dispersion cycles. Under these extraction conditions, the proposed method was able to provide a good linearity (R2 ≥ 0.9994) within the range of 0.5-2500.0 ng mL-1, low detection limits (0.1-0.5 ng mL-1), good extraction replicability (relative standard deviations below 3.5%, n = 7), and enrichment factors of 97-118. Finally, the developed method was successfully used for determining the mentioned analytes in Melissa officinalis samples. Recoveries for all compounds in real samples were between 82.5% and 91.8.