Abstract In present work, amorphous carbon nanoparticles have been prepared by a facile method and used as an efficient and cheap sorbent in dispersive solid phase extraction coupled with dispersive liquid–liquid microextraction. The proposed method is used as a sample preparation technique for the extraction and preconcentration of some pesticides from different fruit juice samples prior to their determination by gas chromatography–flame ionization detection. In this method, the sample solution containing the analytes is vortexed after adding a few mg of the sorbent. After centrifugation, the solution is discarded and the analytes–loaded sorbent is eluted with iso–propanol. Then to more concentrate the analytes, the obtained eluent is mixed with 1,2–dibromoethane at µL–level (as a preconcentration solvent) and rapidly injected into deionized water. After centrifugation, the droplets of 1,2–dibromoethane containing the analytes are sedimented at the bottom of test tube. This phase is taken and injected into the separation system for quantitative analysis. The properties of the sorbent were characterized using techniques such as X–ray diffraction, Fourier transform infrared spectrophotometry, and scanning electron microscopy. Under optimum conditions, limits of detection and quantification were achieved in the ranges of 0.83–1.16 and 2.8–4.0 ng mL–1, respectively. Relative standard deviations were less than 8% for intra– (n = 6) and inter–day (n = 4) precisions at a concentration of 10 ng mL–1 of each analyte. Extraction recoveries and enrichment factors of the analytes ranged from 61 to 83% and 610–832, respectively.

中文翻译：

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一种新的、简便的制备无定形碳纳米粒子的方法及其作为一种高效廉价的吸附剂从果汁中提取一些农药的应用

摘要 在目前的工作中，无定形碳纳米粒子已通过一种简便的方法制备，并将其用作分散固相萃取与分散液-液微萃取相结合的高效廉价吸附剂。所提出的方法用作样品前处理技术，用于在气相色谱-火焰电离检测法测定前从不同果汁样品中提取和预浓缩某些农药。在该方法中，含有分析物的样品溶液在加入几毫克吸附剂后进行涡旋。离心后，弃去溶液并用异丙醇洗脱载有分析物的吸附剂。然后为了更浓缩分析物，将获得的洗脱液与 1、µL 级的 2-二溴乙烷（作为预浓缩溶剂）并快速注入去离子水中。离心后，含有分析物的 1,2-二溴乙烷液滴沉淀在试管底部。该相被取出并注入分离系统进行定量分析。使用 X 射线衍射、傅里叶变换红外分光光度法和扫描电子显微镜等技术表征吸附剂的性质。在最佳条件下，检测限和定量限分别在 0.83–1.16 和 2.8–4.0 ng mL–1 范围内实现。每种分析物浓度为 10 ng mL-1 时，日内 (n = 6) 和日间 (n = 4) 精密度的相对标准偏差小于 8%。