Abstract: This study developed a method for the simultaneous determination of 19 phthalate esters (PAEs) and 9 phthalate monoesters (mPAEs) in aquatic products using ultra-high performance liquid chromatography-high-resolution mass spectrometry (UPLC-HRMS) after quick, easy, cheap, efficient, rugged and safe (QuEChERS) pretreatment. The results indicated that the average recoveries for 19 PAEs and 9 mPAEs in spiked matrices were 71%–120% and 87%–119%, with detection limits of 1–48 and 1–6 ng/g md, respectively. It was noted that under optimized chromatographic conditions, baseline separation of the isomers of four PAEs and one mPAE was achieved, especially diisobutyl phthalate (DIBP) versus dibutyl phthalate (DBP), and monoisobutyl phthalate (MIBP) versus monobutyl phthalate (MBP). This method was applied to 17 commercially available aquatic products in Guangzhou, and the results showed that the detection rates of six PAEs, including DBP, DIBP, di(2-ethylhexyl) phthalate, bis(4-methyl-2-pentyl) phthalate, butyl benzyl phthalate, di-n-pentyl phthalate, as well as three mPAEs, including MBP, MIBP, and mono(2-ethylhexyl) phthalate, were relatively high. This method is simple to operate, with high sensitivity, providing important technical support for the detection and risk assessment of PAEs and mPAEs in aquatic products.

Key words: phthalate esters; phthalate monoester; ultra-high performance liquid chromatography-high-resolution mass spectrometry; aquatic products