title: Thin metal organic frameworks coatings by cathodic electrodeposition for solid-phase microextraction and analysis of trace exogenous estrogens in milk.
abstract: Cathodic electrodeposition (CED) has received great attention in metal-organic frameworks (MOFs) synthesis due to its distinguished properties including simplicity, controllability, mild synthesis conditions, and product continuously. Here, we report the fabrication of thin (Et3NH)2Zn3(BDC)4 (E-MOF-5) film coated solid phase microextraction (SPME) fiber by a one-step in situ cathodic electrodeposition strategy. Several etched stainless steel fibers were placed in parallel in order to achieve simultaneously electrochemical polymerization. The influence of different polymerization parameters Et3NHCl concentration and polymerization time were evaluated. The proposed method requires only 20 min for the preparation of E-MOF-5 coating. The optimum coating showed excellent thermal stability and mechanical durability with a long lifetime of more than 120 repetitions SPME operations, and also exhibited higher extraction selectivity and capacity to four estrogens than commonly-used commercial PDMS coating. The limits of detection for the estrogens were 0.17-0.56 ng mL(-1). Fiber-to-fiber reproducibility (n = 8) was in the respective ranges of 3.5%-6.1% relative standard deviation (RSD) for four estrogens for triplicate measurements at 200 ng mL(-1). Finally, the (E-MOF-5) coated fiber was evaluated for ethinylestradiol (EE2), bisphenol A (BPA), diethylstilbestrol (DES), and hexestrol (HEX) extraction in the spiked milk samples. The extraction performance of this new coating was satisfied enough for repeatable use without obvious decline.
authors: Department of Food Science & Technology, Ningbo University, Ningbo 315211, China.
authors: Hangzhen
authors: H
authors: Lan
authors: Department of Food Science & Technology, Ningbo University, Ningbo 315211, China; Department of Food Science & Nutrition, Nanjing Normal University, Nanjing 210097, China. Electronic address: daodongpan@163.com.
authors: Daodong
authors: D
authors: Pan
authors: Department of Food Science & Technology, Ningbo University, Ningbo 315211, China.
authors: Yangying
authors: Y
authors: Sun
authors: Department of Food Science & Nutrition, Nanjing Normal University, Nanjing 210097, China.
authors: Yuxing
authors: Y
authors: Guo
authors: Department of Food Science & Technology, Ningbo University, Ningbo 315211, China.
authors: Zhen
authors: Z
authors: Wu
mesh_terms: D000818:Animals; D004566:Electrodes; D004595:Electroplating; D004967:Estrogens / Q000032:analysis*; D000073396:Metal-Organic Frameworks / Q000737:chemistry*; D008892:Milk / Q000737:chemistry*; D052617:Solid Phase Microextraction
chemical_list: D004967:Estrogens; D000073396:Metal-Organic Frameworks
keywords: Cathodic electrodeposition; Estrogens; High performance liquid chromatography; Metal organic framework; Solid-phase microextraction