Development and application of a solid phase extraction method for the determination of phthalates in artificial saliva using new synthesised microspheres

Abstract

This paper describes a method for the determination of six phthalate esters (PEs) in artificial saliva using solid phase extraction (SPE) and gas chromatography–mass spectrometry (GC–MS). A new material was developed to isolate the PEs from artificial saliva. Poly(ethylene glycol dimethacrylate-N-methacryloyl-L-tryptophan methyl ester) (poly(EGDMA-MATrp)) microspheres (average diameter = 106–300 μm) were synthesised and characterised.Several different parameters, such as pH, adsorption time and adsorbent amount, which affect SPE, were carefully optimised by central composite design (CCD). The best analytical conditions for the simultaneous determination of the analytes from a spiked artificial saliva sample were found to be a pH of 6.8, an adsorption time of 90 min, and an adsorbent amount of 1.8 g L−1, using dichloromethane as the elution solvent. These conditions were applied to study the migration of PEs found on various children's toys into saliva.