负载咪唑型离子液体硅胶吸附材料制备及应用研究

制备了3种取代咪唑键合的硅胶负载型离子液体(甲基咪唑-SIL、氨丙基咪唑-SIL及十二烷基咪唑-SIL),比较了其对水中双酚A(BPA)的吸附能力。在该研究的实验条件下,BPA在十二烷基咪唑-SIL与水溶液之间的分配系数K_d值高达(2.58±0.02)×10³ L/kg,氨丙基咪唑-SIL、甲基咪唑-SIL的K_d值也分别达到(2.26±0.28)×10、(2.71±0.16)×10 L/kg。采用甲醇为洗脱液,可以对十二烷基咪唑-SIL相中的BPA进行有效回收,2次洗脱的合并回收率为106.7%±4.8%。以十二烷基咪唑-SIL作为被动采样装置的接收相,对污水处理厂出水中BPA进行了被动采样监测应用的微宇宙实验研究。结果表明,在实验周期内,十二烷基咪唑-SIL被动采样器对水体中BPA的被动采集呈线性,其采集速率为0.33 L/d,与以HLB为接收相的商品化被动采样器接近,并且同HLB固相萃取填料相比,离子液体接收相对BPA的采集更具选择性,基质效应较小,可作为被动采样监测装置的理想接收相材料。

Preparation of Supported Ionic Liquids on Silica: Application of Passive Sampling for Bisphenol A in Water

Passive sampling is highly complimentary to spot sampling in environmental analysis. Three supported ionic liquids (SILs) based on different substitution imidazolium immobilized on silica were prepared for the development of passive sampling from aqueous solution, including methylimidazolium-SIL, aminopropylimidazolium-SIL, and dodecylimidazolium-SIL. The adsorption of biphnol-A (BPA) from aqueous solution by the three SILs were compared, and the K_d value of dodecylimidazolium-SIL was (2.58±0.02)×10³ L/kg, whereas aminopropylimidazolium-SIL and methylimidazolium-SIL had K_d values that were (2.26±0.28)×10 L/kg and (2.71±0.16)×10 L/kg, respectively. Satisfied recovery (106.7%±4.8%) was obtained by a simple and reliable sample pretreatment method using methanol as eluting solution. Using dodecylimidazolium-SIL as the receiving phase of passive samplers, which were used for sampling BPA from effluent of a wastewater treatment plant in laboratory microcosm experiments. The kinetic studies showed an integrative uptake up to 7 days. The sampling rate for BPA was 0.33 L/d, which can be comparable to other commercial sorbents. Dodecylimidazolium-SIL can be used as perfectly receiving phase of passive sampling device, and it has better selectiveness for BPA sampling and lower matrix effect compared with the Oasis HLB sorbent.