Department of Analytical Chemistry, Institute of Chemistry, Saint Petersburg State University, SPbSU, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia.
Department of Analytical Chemistry, Institute of Chemistry, Saint Petersburg State University, SPbSU, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia.
Talanta. 2022 Jan 15;237:122968. doi: 10.1016/j.talanta.2021.122968. Epub 2021 Oct 14.
A microextraction pretreatment for powdered milk analysis, relying on the formation of a natural deep eutectic solvent is proposed. It relies on the in situ hydrolysis of milk fats (triglycerides) which yields fatty acids as precursors in the formation of the natural deep eutectic solvent. As a proof-of-concept, the innovation was applied to the determination of thirteen polycyclic aromatic hydrocarbons in powdered milk samples by HPLC with fluorometric detection. The alkaline hydrolysis of milk triglycerides minimized sample matrices interference through removal of proteins and fats, and led to formation of natural deep eutectic solvent precursors (fatty acids) directly from the sample components. Addition of only one precursor (terpenoid) was then required. Menthol and thymol (natural terpenoids) were investigated as deep eutectic solvent precursors for microextraction of polycyclic aromatic hydrocarbons. Under the selected experimental conditions, limits of detection were estimated within the 0.002-0.09 μg kg range. The innovation provided satisfactory (70-91%) extraction of hydrophobic analytes from complex powdered milk matrices containing hydrophobic components (triglycerides) without the need for hazardous organic solvents. The RSD values were <5.2%.
提出了一种基于天然深共晶溶剂形成的奶粉分析微萃取预处理方法。它依赖于牛奶脂肪（甘油三酯）的原位水解，生成脂肪酸作为天然深共晶溶剂形成的前体。作为概念验证，该创新方法应用于高效液相色谱-荧光检测法测定奶粉样品中 13 种多环芳烃。通过碱性水解牛奶甘油三酯，通过去除蛋白质和脂肪，最大限度地减少了样品基质的干扰，并直接从样品成分中生成天然深共晶溶剂前体（脂肪酸）。然后只需要添加一种前体（萜烯）。薄荷醇和百里酚（天然萜烯）被研究作为微萃取多环芳烃的深共晶溶剂前体。在所选择的实验条件下，检测限估计在 0.002-0.09μg kg 范围内。该创新方法在不需要危险有机溶剂的情况下，从含有疏水成分（甘油三酯）的复杂奶粉基质中对疏水性分析物进行了令人满意的（70-91%）萃取。相对标准偏差（RSD）值<5.2%。
