Abstract: A reliable gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of 14 phthalic acid esters (PAEs) in imitation jewellery. The influences of sample pretreatment methods including microwave extraction, ultrasonic extraction, accelerated solvent extraction (ASE) and Soxhlet extraction on the determination of PAEs were investigated. The migration risk of dibutyl phthalate (DBP), bis(2-ethyl hexyl) phthalate (DEHP) and dioctyl phthalate (DOP) in plastic imitation jewellery was investigated under the simulated body temperature and sweat environment within 0 h to 168 h. The results showed that the target compounds can be effectively extracted with hexane-acetone (1:1, v/v) under microwave extraction for 35 min. The limit of quantification (LOQ) of the method was 5 mg/kg for 12 PAEs (25 mg/kg for diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP)). The calibration curves were linear within 0.1~50 mg/L (0.5~250 mg/L for DINP and DIDP) with the correlation coefficients above 0.99. The recoveries ranged from 90.95% to 98.67% at three spiked levels. The migration risk of DEHP was higher than DBP and DOP with 0.75% dissolved after soaking for 72 h under the simulated conditions. The sensitivity, recovery and selectivity of the method can meet the requirements of the practical work.

Key words: imitation jewellery, microwave extraction, migration risk, phthalic acid esters (PAEs) , gas chromatography-mass spectrometry (GC-MS)