Biopolymer-imidazolium based dicationic ionic liquid modified clay bionanocomposite coating for solid-phase microextraction of phthalate esters

In this study, biopolymer-ionic liquid modified clay bionanocomposite was used as a coating for solid phase microextraction fiber to improve the analysis of plasticizers. Montmorillonite (MMT) clay intercalated with carboxymethyl cellulose (CMC) and dicationic imidazolium-based ionic liquid (Im-DIL) was coated onto an etched and hydroxyl functionalized stainless steel wire. The prepared MMT/CMC/Im-DIL coated fiber was assessed for the determination of six phthalate esters (PAEs) using direct immersion solid-phase microextraction (DI-SPME) with gas chromatography/mass spectrometer (GC/MS). Compared to MMT, MMT/CMC, MMT/Im-DIL, MMT/CMC/Im-DIL coating displayed much better extraction performance (>nearly 486–20 times). Under optimized conditions, the proposed method performed wide linearity (0.01–400.0 µg L-1), low limit of detection (1.0 ng L-1), satisfactory extraction repeatability (RSD%, ⩽ 3.86) and preparation repeatability (RSD%, ⩽ 5.79). The proposed method was applied successfully for analyzing of PAEs in beer, mineral water and carbonated lemonade drink.