Synthesis of SiO2@MOF-199 as a Fiber Coating for Headspace Solid-Phase Microextraction of Phthalates in Plastic Bottled Milk
In this paper, SiO 2 @MOF-199 composite with core–shell structure was prepared by in-situ growth of MOF-199 on the surface of SiO 2 microspheres, and SiO 2 @MOF-199 coated fiber was prepared for headspace solid phase microextraction (HS-SPME) of phthalate esters (PAEs) in plastic bottled milk. The prepared SiO 2 @MOF-199 has both mesoporous structure of SiO 2 and microporous structure of MOF-199. The hierarchical porous structure not only gives the analyte higher adsorption performance, but also improves the diffusion rate of the analyte in SiO 2 @MOF-199. The coated fibers have good thermal stability and are relatively uniform in size and structure. The extraction conditions of the prepared fibers for PAEs were optimized by single factor optimization and response surface Box-Behnken design. Under optimized conditions, the fiber displays wide linear ranges of PAEs (dimethyl phthalate, diethyl phthalate and diallyl phthalate are 5–800 ng L −1 , di-n-butyl phthalate, butyl benzyl phthalate and di-n-octyl phthalate are 50–1000 ng L −1 ), low limits of detection (0.3–19.8 ng L −1 ), and high enrichment factors (325–2089). The intra-day and inter-day relative standard deviations (RSD) for PAEs extractions using a single fiber were (4.7–8.5%) and (5.7–9.1%), respectively. The fiber-to-fiber reproducibility for three fibers prepared in parallel was 7.2–11.3% (RSD). The method was successfully applied to the extraction of PAEs from plastic bottled milk and to the quantitation by a gas chromatograph with a flame ionization detector. The average recoveries were 84.0% to 105%.
危险品化学品经营许可证（带存储）