Simultaneous extraction of six phthalic acid esters from polyethylene terephthalate (PET) bottled water using poly (ionic liquid) functionalised silica coated-iron oxide nanoparticles: a risk assessment study

ABSTRACT

In this research, a poly (ionic liquid) functionalised silica-coated magnetic nanoparticles were synthesised for the first time and utilised as a novel adsorbent for the simultaneous extraction of six phthalic acid esters from polyethylene terephthalate bottled drinking water samples. The adsorbent was prepared by grafting poly (1-benzyl-3-vinyl-1 H-imidazol-3-ium chloride) onto silica-coated Fe₃O₄nanoparticles via Cu(0)-mediated reversible-deactivation radical polymerisation method. Various techniques were used to characterise the synthesised nanomaterials. A qualitative analysis was performed using ultra-performance liquid chromatography triple–quadrupole tandem mass spectrometry. Response surface methodology based on central composite design was used to optimise the extraction procedure and the optimised condition for each factor was; pH of3.9, 22 mg of adsorbent, 3.5 min extraction time, 3 min desorption time, 340 µL of elution solvent (methanol).The results of the validation of the method indicated its acceptable accuracy (88.6-100.1%), good linearity (r  > 0.995), satisfactory repeatabilities (RSDs ≤ 6% for intra- and inter–day precisions) and high enrichment factors (535–572). The limits of detection and limits of quantification of the proposed method achieved were 1.1-4.6 ngL^–1and 3.6-15.3 ngL^–1, respectively. In this study, six common PAEs, including dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzyl butyl phthalate, bis (2-ethylhexyl) phthalate, and di-n–octyl phthalate, were found in PET bottled water within the range of 0.21-0.94 μgL^–1, under different storage conditions. Nevertheless, only a negligible risk is caused by the PAEs in PET bottled water for consumers following the recommendations, such as storing at a common place (25°C), in a short period away from the sun.

KEYWORDS:

• Magnetic solid-phase extraction
• modified magnetic nanoparticles
• phthalic acid esters analysis
• risk assessment
• ultra-performance liquid chromatography–tandem mass spectrometry

Acknowledgments

The authors are grateful to the anonymous reviewers for their valuable suggestions.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

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