Institute of Chemistry and Technical Electrochemistry, Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, 60-965 Poznan, Poland.
Molecules. 2024 Sep 26;29(19):4573. doi: 10.3390/molecules29194573.
An eco-friendly method for the determination of sweeteners (aspartame, acesulfame-K) and preservatives (benzoic acid, sorbic acid, methylparaben, ethylparaben) in functional beverages and flavoured waters using thin film microextraction (TFME) and high-performance liquid chromatography with UV detection (HPLC-UV) was proposed. A series of fourteen green and renewable solidified natural deep eutectic solvents (NADESs) were prepared and tested as 'eutectosorbents' in TFME for the first time. In the proposed method, the NADES containing acetylcholine chloride and 1-docosanol at a 1:3 molar ratio was finally chosen to coat a support. Four factors, i.e., the mass of the NADES, pH of the samples, extraction time, and desorption time, were tested in the central composite design to select the optimal TFME conditions. Limits of detection were equal to 0.022 µg mL for aspartame, 0.020 µg mL for acesulfame-K, 0.018 µg mL for benzoic acid, 0.026 µg mL for sorbic acid, 0.013 µg mL for methylparaben, and 0.011 µg mL for ethylparaben. Satisfactory extraction recoveries between 82% and 96% were achieved with RSDs lower than 6.1% (intra-day) and 7.4% (inter-day). The proposed 'eutectosorbent' presented good stability that enabled effective extractions for 16 cycles with recovery of at least 77%. The proposed NADES-TFME/HPLC-UV method is highly sensitive and selective. However, the use of a solid NADES as a sorbent, synthesized without by-products, without the need for purification, and with good stability on a support with the possibility of reusability increases the ecological benefit of this method. The greenness aspect of the method was evaluated using the Complex modified Green Analytical Procedure Index protocol and is equal to 84/100.
提出了一种使用薄膜微萃取（TFME）和带有紫外检测的高效液相色谱（HPLC-UV）测定功能饮料和调味水中甜味剂（阿斯巴甜、乙酰磺胺酸钾）和防腐剂（苯甲酸、山梨酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯）的环保方法。首次将一系列 14 种绿色可再生的固态天然深共晶溶剂（NADES）作为“共晶吸收剂”用于 TFME。在所提出的方法中，最终选择了含有氯化乙酰胆碱和 1-二十二烷醇，摩尔比为 1:3 的 NADES 来涂覆支撑体。在中心复合设计中测试了四个因素，即 NADES 的质量、样品的 pH 值、萃取时间和洗脱时间，以选择最佳的 TFME 条件。检测限分别为阿斯巴甜 0.022µg·mL-1、乙酰磺胺酸钾 0.020µg·mL-1、苯甲酸 0.018µg·mL-1、山梨酸 0.026µg·mL-1、对羟基苯甲酸甲酯 0.013µg·mL-1、对羟基苯甲酸乙酯 0.011µg·mL-1。萃取回收率在 82%至 96%之间，日内 RSD 低于 6.1%，日间 RSD 低于 7.4%。所提出的“共晶吸收剂”具有良好的稳定性，可进行至少 16 次有效萃取，回收率至少为 77%。所提出的 NADES-TFME/HPLC-UV 方法具有较高的灵敏度和选择性。然而，使用固态 NADES 作为吸附剂，无需副产物合成，无需纯化，在具有可重复使用性的支撑体上稳定性良好，增加了该方法的生态效益。该方法的绿色度使用复杂的改进绿色分析程序指数协议进行评估，等于 84/100。
