A novel magnetic extractant, PEG 4000 modified Fe₃O₄nanomaterial that coated with dianionic amino acid ionic liquid (Fe₃O₄@[email protected]), was successfully synthesized and characterized. X-ray diffraction (XRD), transmission electron microscope (TEM), vibrating sample magnetometer (VSM), fourier transform infrared spectrometry (FT-IR), thermal gravimetric analysis (TGA) and zeta potentials were used to confirm that the novel nanocomposite was successfully synthesized. Subsequently, the prepared Fe₃O₄@[email protected] nanocomposite was used as the extractant for trypsin coupled with magnetic solid-phase extraction (MSPE). The concentrations of trypsin in the supernatant were detected by UV–vis spectrophotometer at 278 nm. The extraction ability turned out to be better than the other four kinds of extractants prepared in this work. Furthermore, the influence of a series of factors, such as extraction time and temperature, initial trypsin concentration, the value of pH and ionic strength, was systematically investigated. Under the optimal extraction condition, the extraction capacity for trypsin could reach up to 718.73 mg/g, absolutely higher than that of other adsorbents reported. This satisfactory extraction capacity could be maintained unchangeable after at least eight days, and kept over 90% of initial extraction capacity after eight recycles. What's more, the activity of trypsin after extraction retained 92.29% of initial activity, verifying the biocompatibility of the prepared extractant. Finally, the developed Fe₃O₄@[email protected] method was successfully applied to the real sample analysis with satisfactory results. All of above proves the potential value of Fe₃O₄@[email protected] in the analysis of biomass.

成功地合成并表征了一种新型的磁性萃取剂PEG 4000修饰的Fe ₃ O ₄纳米材料，该材料包覆有双阴离子氨基酸离子液体（Fe ₃ O ₄ @ [受电子邮件保护]）。使用X射线衍射（XRD），透射电子显微镜（TEM），振动样品磁力计（VSM），傅立叶变换红外光谱（FT-IR），热重分析（TGA）和Zeta电位来确认该新型纳米复合材料是成功合成。随后，制备了Fe ₃ O ₄@ [受电子邮件保护的]纳米复合材料被用作胰蛋白酶与磁性固相萃取（MSPE）的萃取剂。用紫外可见分光光度计在278 nm处检测上清液中胰蛋白酶的浓度。事实证明，其提取能力优于本工作中制备的其他四种提取剂。此外，系统地研究了萃取时间和温度，胰蛋白酶的初始浓度，pH值和离子强度等一系列因素的影响。在最佳提取条件下，胰蛋白酶的提取量可达到718.73 mg / g，绝对高于报道的其他吸附剂。至少八天后，这种令人满意的提取能力可以保持不变，经过八次循环后，仍保持了最初提取量的90％以上。此外，提取后胰蛋白酶的活性保留了初始活性的92.29％，从而验证了所制备提取剂的生物相容性。最后，发达的铁₃ O ₄ @ [email protected]方法已成功应用于实际样品分析，结果令人满意。以上证明了Fe ₃ O ₄ @ [电子邮件保护]在生物量分析中的潜在价值。