Abstract A new hybrid material was synthesized including magnetic graphene oxide/multiwalled carbon nanotube core shell (GO/MWCNT/Fe3O4/SiO2) and used as magnetic solid phase extraction adsorbent for separation and pre-concentration of paracetamol and caffeine subsequent detection by high performance liquid chromatography. The morphology, composition, and properties of the synthesized hybrid material was characterized by Fourier transform infrared spectrometry, Raman spectrometry, X-ray diffraction spectrometry, scanning electron microscopy, mapping photographs and BET surface area analysis. The experimental variables on the extraction efficiency were studied and optimized. The optimum conditions for quantitative extraction of paracetamol and caffeine were obtained as of adsorbent amount, 70 mg; pH, 8.0; and elution with 1 mL of methanol by vortex mixer for 60 s. Validation experiments showed that the developed method had good linear ranges 5–800 ng mL−1 for caffeine and 10–1000 ng mL−1 for paracetamol, respectively. The limits of detection were found as 1.48 and 3.32 ng mL−1 for caffeine and paracetamol, respectively. The accuracy of the developed magnetic solid phase extraction method was proved by addition-recovery tests by using model solutions and the developed method was successfully applied for the determination of paracetamol and caffeine in synthetically prepared urine and waste water samples.

中文翻译：

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使用由氧化石墨烯/多壁碳纳米管/Fe3O4/SiO2组成的核壳杂化材料磁性固相萃取合成尿液和废水样品中的痕量扑热息痛和咖啡因

摘要 合成了一种包含磁性氧化石墨烯/多壁碳纳米管核壳（GO/MWCNT/Fe3O4/SiO2）的新型杂化材料，并将其用作磁性固相萃取吸附剂，用于对乙酰氨基酚和咖啡因的分离和预浓缩，随后通过高性能液体进行检测。色谱法。通过傅里叶变换红外光谱、拉曼光谱、X 射线衍射光谱、扫描电子显微镜、映射照片和 BET 表面积分析对合成的杂化材料的形貌、组成和性质进行了表征。对影响萃取效率的实验变量进行了研究和优化。对乙酰氨基酚和咖啡因定量提取的最佳条件为吸附剂量为70 mg；pH，8.0；并用 1 mL 甲醇通过涡旋混合器洗脱 60 秒。验证实验表明，所开发的方法对咖啡因具有良好的线性范围，分别为 5-800 ng mL-1 和对乙酰氨基酚的 10-1000 ng mL-1。咖啡因和扑热息痛的检测限分别为 1.48 和 3.32 ng mL-1。使用模型溶液进行加成-回收试验证明了所建立的磁性固相萃取方法的准确性，并成功地将所建立的方法应用于合成制备的尿液和废水样品中扑热息痛和咖啡因的测定。咖啡因和扑热息痛分别为 32 ng mL-1。使用模型溶液进行加成-回收试验证明了所开发的磁性固相萃取方法的准确性，并成功地将所开发的方法应用于合成制备的尿液和废水样品中扑热息痛和咖啡因的测定。咖啡因和扑热息痛分别为 32 ng mL-1。使用模型溶液进行加成-回收试验证明了所建立的磁性固相萃取方法的准确性，并成功地将所建立的方法应用于合成制备的尿液和废水样品中扑热息痛和咖啡因的测定。