The application of directly suspended droplet microextraction for the evaluation of phthalic acid esters in cow’s milk by gas chromatography mass spectrometry

•A simple and economic method was developed to evaluate 16 PAEs at the μg/kg level in a complicated milk matrix by DSDME-GC–MS.•Optimal conditions for DSDME of PAEs were obtained.•The proposed method was successfully applied to the analysis of PAEs in real milk samples.

A simple and rapid method was developed for evaluating 16 phthalic acid esters (PAEs) at the μg/kg level in a complex milk matrix using directly suspended droplet microextraction-gas chromatography mass spectrometry (DSDME-GC–MS). The different parameters for extraction and for the DSDME experiment were optimized, including You are free to submit the revised manuscript at a later date as a new submission.10 g/L trichloroacetic acid concentration, 100 μL cyclohexane micro-droplet organic solvent, 1100 rpm stirring speed, 10 min extraction time and no salt amount. Validation experiments showed good linearity (γ > 0.9878, 0.002–0.4 μg/mL), satisfactory precision (RSD < 11%), and good accuracy (relative recovery of 70.2–108%) when analyzing milk samples using the optimized method. The limits of detection (LODs) ranged between 0.001 and 0.2 μg/L, and the limits of quantification (LOQs) ranged between 0.003 and 0.7 μg/L for 15 PAEs. Dinonyl phthalate (DINP) had a low response and did not have good linearity. The proposed method was successfully applied for the analysis of PAEs in real milk samples.