Contamination of Phthalic Acid Esters (PAEs) in Surface Sediment Samples Collected from Rao Cai River in Ha Tinh, Vietnam

In this report, the solid phase extraction technique combined with the gas chromatography-mass spectrometry method (GC-MS) was optimized to determine the contamination of nine phthalic acid esters (PAEs) in the surface sediment samples collected from Rao Cai River in Ha Tinh, Vietnam. The method detection limits (MDLs) were from 2.0 to 6.0 ng/g-dry weight (ng/g-dw). The recoveries of surrogate standards (PAE-d4) in both blank and real samples ranged from 79.6 to 94.3% (RSD < 8.7%). The total concentration of PAEs in the surface sediment samples was in the range of 72.4-1390 ng/g-dw (mean/median: 561/552 ng/g-dw). Among PAEs, di-(2-ethyl)hexyl phthalate (DEHP) was detected at the highest level in all samples. In contrast, dimethyl phthalate (DMP), diethyl phthalate (DEP), and dipropyl phthalate (DPP) were found at low frequency and concentration. Moreover, the risk quotient of PAEs in sediments was estimated based on the measured concentrations. Diisobutyl phthalate (DiBP) posed a medium risk for fish.