Preparation And Application Of Mono-phthalate Magnetic Molecularly Imprinted Polymers

Phthalates（PAEs）are widely used as plasticizers and are easily released into food,water,air,dust and soil.PAEs are rapidly metabolized into phthalate monoesters（m PAEs）and excreted in urine after entering into human boby.Therefore,the concentration of m PAEs in urine is usually used to assess the exposure level of human PAEs.The urine matrix is very complex,and effective sample pretreatment is a key step in the detection of m PAEs.In this paper,two kinds of magnetic molecularly imprinted polymers of phthalate monoesters were prepared and applied to separate and enrich m PAEs from urine.1.Magnetic molecularly imprinted polymer（MMIP）was successfully synthesized with methacrylic acid as a functional monomer and monohexyl phthalate（MHP）as dummy template molecule by surface imprinting technology.In the synthese process,ethylene glycol dimethacrylate and 2,2-azobisiso butyronitrile were used as a crosslinking agent and initiator,respectively.The obtained MMIPs were characterized and used as solid phase extraction material to extract monobutyl phthalate（MBP）and mono benzyl phthalate（MBz P）from urine.The results showed that the MMIPs had specific recognition ability,high adosorption and good reusability.The total adsorption capacity of the MMIPs for MBP and MBz P is 60.5 mg/g and the saturation magnetization is 34.5 emu/g,which is enough for the MMIPs to be separated from solutions by a magnet.Based on HPLC-UV method,good linearities were obtained in the range of 0.0005～0.2 mg/m L for MBP and MBz P with high correlation coefficient（R²≥0.9997）.The recoveries of MBP and MBz P were between 81.6%to 104%,and the relative standard deviation is less than 6.5%.2.Magnetic molecularly imprinted polymerswith good specific adsorbent capacity towards m PAEs were successfully prepared by sol-gel reaction and surface imprinting technology.Tetraethyl orthosilicate（TEOS）,（3-Aminopropyl）triethoxysilane（APTES）and monohexyl phthalate（MHP）were used as cross linker,functional monomer and dummy template molecule,respectively.The obtained imprinting polymers were characterized and used as solid phase extraction material to extract five m PAEs from urine.The results showed that this preparation method is simple and efficient.The complicated surface modification of Fe₃O₄ was avoided and the synthesis time is shortened to 1 h.The obtained MMIPs had high recognition ability,good adsorption capacity（124.5mg/g）,relatively good regeneration capacity,and fast adsorption rates（about 30min to equilibrium）to m PAEs.Three human urine samples were pretreated using the obtained MMIPs and analyzed by high performance liquid chromatography（HPLC）method.Good linearities were obtained in different range for the five m PAEs（MMP,MEP,and MBP:0.001～0.1mg/m L;MBz P:0.001～0.08 mg/m L;MEHP:0.001～0.05 mg/m L）.The recoveries of five m PAEs at all spiked levels ranged from 80.0%to 101.0%,and the relative standard deviation is less than 6.6%.