Abstract This research describes the spectrophotometric determination of methylene blue (MB) after shaker-assisted liquid-liquid microextraction combined with back-extraction (SALLME-BE). A hydrophobic deep eutectic solvent (DES) was used for extraction of MB from alkaline solutions (0.5 M NaOH). Then, the extracted dye was back-extracted into a hydrochloric acid solution (2 M). Decanoic acid and methyltrioctylammonium bromide were used, respectively as hydrogen bond donor and hydrogen bond acceptor constituents of the hydrophobic DES. The calibration graph was linear in the range of 2–170 ng mL−1. The recovery analysis of wastewater and river water samples verified that this method is practical for environmental monitoring.

中文翻译：

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使用深共熔溶剂摇床辅助液液微萃取亚甲基蓝，然后反萃取和分光光度法测定

摘要 本研究描述了振动器辅助液-液微萃取结合反萃取 (SALLME-BE) 后亚甲基蓝 (MB) 的分光光度法测定。疏水性低共熔溶剂 (DES) 用于从碱性溶液 (0.5 M NaOH) 中提取 MB。然后，将提取的染料反提取到盐酸溶液 (2 M) 中。癸酸和甲基三辛基溴化铵分别用作疏水性DES的氢键供体和氢键受体成分。校准图在 2–170 ng mL-1 范围内呈线性。废水和河水样品的回收率分析证明该方法适用于环境监测。