Extraction Property And Preparation Of Dicationic Imidazolium Polymeric Ionic Liquid Based Magnetic Solid-phase Extraction Materil

As a new sample preparation technique, magnetic solid-phase extraction(MSPE) using ionic liquid(IL) modified-magnetic particles as sorbent has attracted more and more attention in separation and analysis field. The technique possesses some advantages of MSPE such as simple operation, fast extraction and low matrix interference, as well as unique characteristics of IL including tailored structure and easy chemical functionalization. In this paper,novel dication imidazoium polymeric ionic liquid(PIL) based magnetic materias by chemical-bonding and layer-by-layer assembly were prepared and were used as adsorbent of MSPE for extraction and enrichment of organic pollutants.A poly(ionic liquid)(poly-(1,8-octanediyl-3,3’-bis-l-vinylimidazo- lium dibromide), DVD) cross-linked magnetic particles(MPs@PIL) as an adsorbent was prepared, and a novel MPs@PIL based MSPE combined with gas chromatography-mass spectrometry(GC-MS) was developed for the determination and pretreatment of 6 phthalate esters(PAEs) in water and drinks. MPs@PIL was characterized by FT-IR, XRD,TG and VSM. The influences of several experimental variables, including amount of adsorbent, adsorption time, the kind and the volume of desorption, desorption time, ionic strength and the temperature were optimized. Under the optimal conditions, good linearity in the concentration range of 0.4 μg L-1–20 μg L-1 was obtained with a correlation coefficient(R2) >0.9957. Low limits of detection and high enrichment factors varied from 0.0012 ng L-1 to 15.6 ng L-1and from 54.57 to 113.26 respectively. The proposed method has been successfully used to determine 6 PAEs from tap water, mineral water and two tea drinks with relative recoveries of 72.95%-123.54% and RSD of 0.53%–25.38%, respectively.A series of ILs including 1,4-butyanediyl-3,3’-bis-l-vinylimidazolium dibromide(BVD), 1,8-dioctanediyl-3,3’-bis-l-vinylimidazolium dibromide(DVD) and 1,12-lauranediyl-3, 3’-bis-l-vinylimidazolium dibromide(Do VD) were syntheticed and cross-linked on the surface of the triethoxyvinyltriethoxysiane modified magnetic particles(MPs).The obtained three magnetic adsorbents BVD@MPs、DVD@MPs and Do VD@MPs, were characterized by FT-IR, XRD, TG and VSM,.Combining with MSPE and HPLC-UV, DVD@MPs as an example adsorbrnt to extracte and concentrate polycyclic aromatic hydrocarbons(PAHs) and organophosphorus pesticide(OPPs) in water samples.The effects of different variables on extraction efficiency were optimized, including kind of anion, amount of adsorbent, extraction time, kind and the volume of desorption solvent, desorption time and amount of Na Cl. The extraction efficiencies of three adsorbents for PAHs and OPPs were comparedH. UnderH the optimal experimental conditions, LR of parathion was 5 μg L-1-200 μg L-1,LR of the others were 1 μg L-1-100 μg L-1 with R2 of 0.9960-0.9998. LOD and LOQ were 0.24 μg L-1-4 μg L-1 and 0.72 μg L-1-12 μg L-1, respectively. ER and EF were 6.73%-79.08% and 36.73-79.08, respectively. The repeatability of the proposed method was investigated by five times extraction at three concentration level of 2 μg L-1, 10 μg L-1and 50 μg L-1 and RSD were 1.66%-10.24%, 2.83%-7.37% and 2.70%-9.51%, respectively. DVD@MPs-MSPE-HPLC-UV was successfully applied to extract and determine PAHs and OPPs in environmental water samples with relative recoveries and RSD of 78.18%-126.94% and 0.40%-16.02%, respectively.A poly(1-butyl-3-(1-vinylimidazolium-3-octyl)-imidazolium) ionic liquid was synthesized and successfully immobilized onto the surface of the magnetic material layer by layer assembly technique. The new material was charactered by FT-IR, NMR, XRD, and VSM. The extraction efficiency of the material as a new MSPE adsorbent for four OPPs(fenitrothion, parathion, fenthion and phoxim) in environmental water samples was evaluated. Parameters influencing the extraction efficiency, such as the amount of adsorbent, adsorption time, desorption solvent, desorption time and salt addition were optimized by combining with HPLC. Under the optimization conditions, the developed poly(ionic liquid)-MSPE-HPLC method provided a good linear ranges of 5-200 μg L-1 with correlation coefficients of 0.9961-0.9991. LODs and RSD(S/N=5) of four OPPs were 0.25 μg L-1 and 2.59-11.81%. The method also was applied to detect the analytes in three kinds of real environmental samples with satisfactory relative recoveries of 72.41%-111.78% and RSDs of 1.08%-17.93%.