Determination of releasing plasticizers from dental floss using ultrasound–assisted extraction–dispersive liquid–liquid microextraction followed by gas chromatography–flame ionization detector

Recently, the wide existence of phthalate esters in healthcare products has attracted great attention from scientists due to their negative effects on human health. As a result, the current study was carried out to determine the presence of some plasticizers in dental floss such as di-n-butyl phthalate, diethyl phthalate, di-2-ethylhexyl phthalate, di-iso-butyl phthalate, and bis-2-ethylhexyl adipate. The studied analytes were extracted from dental floss by an ultrasound–assisted extraction procedure and then enriched by a dispersive liquid–liquid microextraction method. For this purpose, a piece of dental floss was immersed in acetonitrile under sonication to extract the analytes. Then, the acetonitrile phase containing the extracted analytes was mixed with a proper extraction solvent at µL–level and injected into sodium chloride solution. The extracted analytes were determined by gas chromatography–flame ionization detector and gas chromatography–mass spectrometry. Under the best extraction conditions, limits of detection and quantification were found in the ranges 0.20–0.33 and 0.67–1.1 µg/L in solution and 0.06–0.10 and 0.19–0.33 µg g−1 in dental floss, respectively. Relative standard deviations were in the ranges 4.0–6.5% and 5.1–7.9% for intra-day and inter-day precisions for five replicates at 60 µg/L of each analyte. Enrichment factors and extraction recoveries of the analytes ranged from 350 to 460 and 70–92%, respectively.