Fabrication of Polydopamine-Functionalized Zirconium Dioxide Nanoparticle Coatings for the Sensitive Detection of Phthalate Esters Migrated from Beverage Packaging
Kaili Wang, Liu Han, Jiaxin Liu, Xueqing Ma, Huiju Wang, Tianhong ZhouIntroduction/Objective:
Phthalic acid esters (PAEs), widely used as plasticizers in PVC and other food-contact materials, readily migrate into beverages and pose endocrine-disrupting toxicity. Their trace levels and complex matrices make direct determination difficult. This study aimed to fabricate a polydopamine (PDA) -modified zirconium dioxide nanoparticle (ZrO2NPs) coating on a stainless steel (SS) wire (PDA@ZrO2NPs@SS) as a solid-phase microextraction (SPME) fiber combined with HPLC for the extraction and determination of PAEs migrated from beverage packaging.
Methods:
The PDA@ZrO2NPs@SS fiber was fabricated by potentiostatic deposition of nano-ZrO2 onto a stainless-steel wire followed by dopamine self-polymerization. The fabricated fiber was used for SPME of 6 PAEs, and the analytes were desorbed and determined by HPLC under isocratic elution with a methanol/water (75:25, V/V) mobile phase at 280 nm. Extraction conditions were optimized. The method was validated in terms of linearity, limits of detection (LODs S/N=3), limits of quantification (LOQs S/N=10), recovery, and RSD, and was applied to the determination of PAEs migrated from five beverage packaging samples.
Results:
Under the optimized conditions, the method was linear in the range of 0.05~300 μg/L with a correlation coefficient (r) exceeding 0.9988. The LODs and LOQs were 0.006~0.052 μg/L and 0.019~0.171 μg/L, respectively. Spiked recoveries ranged from 88.1 % to 103.9 %, with relative standard deviations (RSDs) of 6.4 %~8.2 %.
Discussion:
The enrichment capability and coating stability of the fiber arise from the synergy between ZrO2NPs, which provide a large specific surface area and multiple adsorption sites, and the PDA layer, which anchors the nanoparticles via its catechol/amine groups. The wide linear range and low LOD meet the requirements for ultra-trace PAEs determination, while the satisfactory recoveries and low RSDs indicate good accuracy and repeatability. Compared with liquid-liquid extraction and dispersive solid-phase extraction, the proposed method is solvent-free, rapid, and easy to automate.
Conclusion:
The novel PDA@ZrO2NPs@SS fiber was successfully fabricated and coupled with HPLC for the determination of PAEs migrated from beverage packaging. The method is simple, rapid, sensitive, and accurate, and is therefore suitable for the analysis and determination of trace PAEs in real samples.