Abstract:
With strict quality control measures to eliminate background contamination and ensure data validity, the method mentioned by the title was used to determine the contents of 7 phthalate esters (PAEs) and 6 organophosphate esters (OPEs) in soil. The soil sample was air-dried naturally, ground, and sieved, then an aliquot (2.0 g) was taken, and 0.5 g of anhydrous sodium sulfate, 50 µL of the 1.0 mg·L
−1 mixed quantitative internal standard solution containing 7 deuterated PAEs and 4 deuterated OPEs were added, followed by equilibration for 30 min. Then, 10 mL of the
n-hexane-acetone mixed solution at volume ratio of 1∶1 was added, the mixture was shaken for 30 min, sonicated for 10 min, and centrifuged for 5 min, and the supernatant was collected. The extraction was repeated once in the same steps, and the supernatants were combined, and concentrated to approximately 2 mL with nitrogen at 40 ℃. The solution obtained was passed through the Florisil glass solid phase extraction cartridge, eluted with 15 mL of the
n-hexane-acetone mixed solution at volume ratio of 4∶1. The eluate was collected, and evaporated to approximately 0.5 mL with nitrogen at 40 ℃. Then, 50 µL of the 1.0 mg·L
−1 deuterated polycyclic aromatic hydrocarbons mixed injection internal standard solution was added, and the volume of the mixed solution was made up to 1 mL with
n-hexane, followed by determination according to the gas chromatography-mass spectrometry. It was shown that linear relationships between the mass concentrations of PAEs and OPEs and the peak area ratios of target compounds to quantitative internal standards were kept in the range of 5–400 μg·L
−1, with detection limits in the range of 0.30–1.39 ng·g
−1. Tests for recovery was performed using the standard addition method on the quartz sand and soil sample, giving recoveries in the range of 89.2%–110%, and RSDs (
n=6) of the determined values were not more than 10%. The proposed method was applied to the analysis of soil samples from different sources and with different matrices, and the detection rates for diisobutyl phthalate, dibutyl phthalate, and diethyl phthalate were 100% with relatively high detected amounts (84.2–2 795 ng·g
−1).