Abstract A tryptophan ionic liquid (TrpIL) decorated magnetic graphene oxide (Fe3O4@SiO2-GO-TrpIL) nanocomposite has been prepared for magnetic solid-phase extraction of Sudan I–IV before their high performance liquid chromatography (HPLC) analysis. Fe3O4@SiO2 nanoparticles loaded on graphene oxide endow the as-prepared nanocomposite with superparamagnetic performance, benefiting conveniently magnetic separation of the Sudan-absorbed nanocomposites from an aqueous phase. Both TrpIL and grapheme oxide make the Fe3O4@SiO2-GO-TrpIL adsorbent possess high affinity and extraction efficiency toward target analytes, Taking full advantages of the adsorbent, each of Sudan I–IV could be accurately quantified in a linear range of 0.01–0.50 µg mL−1 with the detection limit of 1.0 ng mL−1 under the optimized conditions. A 10-fold enrichment factor was obtained. The present method was employed for the simultaneous determination of Sudan I–IV in chill and water samples with satisfactory results. The thermodynamic and kinetic investigations proved that the targets might be chemisorbed onto the Fe3O4@SiO2-GO-TrpIL nanocomposite. Graphical Abstract

中文翻译：

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基于氨基酸离子液体的磁性固相萃取磁性氧化石墨烯纳米材料-高效液相色谱法同时测定苏丹I-IV

摘要 在高效液相色谱 (HPLC) 分析之前，制备了色氨酸离子液体 (TrpIL) 修饰的磁性氧化石墨烯 (Fe3O4@SiO2-GO-TrpIL) 纳米复合材料，用于苏丹 I-IV 的磁性固相萃取。负载在氧化石墨烯上的 Fe3O4@SiO2 纳米颗粒赋予所制备的纳米复合材料超顺磁性能，有利于从水相中方便地磁分离吸附苏丹的纳米复合材料。TrpIL 和氧化石墨烯使 Fe3O4@SiO2-GO-TrpIL 吸附剂对目标分析物具有高亲和力和提取效率，充分发挥吸附剂的优势，可以在 0.01-0.50 的线性范围内准确定量苏丹 I-IV µg mL-1，优化条件下检测限为 1.0 ng mL-1。获得了 10 倍的富集因子。采用本方法同时测定冰冻样品和水样中的苏丹红I-IV，结果令人满意。热力学和动力学研究证明目标物可能被化学吸附到 Fe3O4@SiO2-GO-TrpIL 纳米复合材料上。图形概要