Development of dispersive solid phase extraction utilizing folic acid as an efficient and green sorbent followed by dispersive liquid-liquid microextraction for the extraction of some plasticizers from aqueous samples.

In this investigation, folic acid has been used as an efficient and green sorbent in dispersive solid phase extraction for the extraction of di(2-ethylhexyl) adipate and three phthalate esters from the plastic-packed liquids before their determination with gas chromatography-flame ionization detection. This is the first report on the application of pure folic acid as a sorbent. In this work, limits of detection and quantification were in the ranges of 0.13-0.46 and 0.43-1.50 µg/L, respectively. Relative standard deviations were in the ranges of 2-5% for intra- (n = 6) and 4-7% for interday (n = 4) precisions at a concentration of 20 µg/L for each analyte. Enrichment factors and extraction recoveries were obtained in the ranges of 365-670 and 45-84%, respectively. Efficiency of the method was evaluated by analyzing the analytes in various plastic-packed liquids.