An environmentally friendly method for the determination of testosterone and methyltestosterone by acid–base-induced deep eutectic solvents liquid–liquid microextraction (DES-ABLLME) combining with high-performance liquid chromatography was established. The deep eutectic solvent (DES) consisting of menthol:lauric acid:decanoic acid (3:1:1) can act as both hydrogen bond donor and hydrogen bond acceptor. In this approach, ammonia solution (NH3•H2O) is used as an emulsifier to react with DESs in the extraction process to generate salt and form milky white solution, achieving high extraction efficiency. Hydrochloric acid was used as a phase separator to change the emulsification state and promote the separation of extraction agent from water phase. A series of parameters were optimized including the volume of DES and the emulsifying agent, glucose concentration as well as hydrochloric acid volume. The method was linear in the range 0.5–100 μg mL−1 with a correlation coefficient (R) of 0.9999, and the limits of detection were 0.067 and 0.2 μg mL−1 for testosterone and methyltestosterone, respectively. This method was applied to analyze testosterone and methyltestosterone in milk samples, and the recoveries were between 89.2 and 108.2%.
Dezhi Yang,Yingdong Wang,Jianbo Peng,Chun Xun,Yaling Yang
A simple, effective and convenient method for determination of phenolic compounds by acid-base induced deep eutectic solvents (DESs) microextraction was developed. The binary and ternary DESs were prepared by a range of fatty acids (C 8 -C 12 ), which can act as hydrogen bond donors and hydrogen bond acceptors simultaneously. The gas-assisted mixing customization provides excellent mixing performance and concentration efficiency through the bubble adsorption mechanism for the handling of large-volume aqueous sample. In extraction process, NH 3 ·H 2 O can act as the emulsifier agent and reacted with DESs to form salts with a cloudy solution, which can obviously improve the extraction efficiency. HCl can act as the phase separation agent, and there is no need to centrifuge, which increases the efficiency of analysis procedure. The factors affected on extraction efficiency were carefully optimized. At optimum conditions and molar ratio of C 8 :C 9 :C 12 (3:2:1), the limit of detections (LODs), the preconcentration factor, the repeatability (RSDs%) were in the range of 0.22–0.53 μg L −1 , 235–244, and 2.6–6.7%, respectively. Finally, the proposed method was applied to analyze four phenolic compounds in real water samples and the recoveries were between 87.4% and 106.6%.
XiuLi Wang,Yinguang Lu,Longyan Shi,Dezhi Yang,Yaling Yang
A quick and simple sample extraction method was demonstrated for the liquid-liquid microextraction of seven phthalate acid esters (PAEs) using acid-base induced deep eutectic solvent (DES) with vortex-mixing assistance. The binary and ternary DESs were prepared by a range of fatty acids (C8-C12) and menthol, which ones act as hydrogen bond donors and acceptors respectively. Fatty acids and menthol served as an extraction solvent and a pH-dependent phase based on the acid-base reaction caused by the adjustment of the pH of the solution. Additionally, the extraction efficiency of the deep eutectic solvent (DES) was improved by adding the emulsifier sodium hydroxide. Hydrochloric acid was used as a phase separation agent. Additionally, the key parameters were optimized through orthogonal array experimental design and statistical analysis. Under the optimal extraction conditions, good linearity of the method was obtained in the concentration range from 1 to100 μg mL −1 for phthalate esters, and preconcentration was completed within 5 min. The limits of detection (LODs) was 1.06–4.55 ng mL −1 , respectively. The spiked recovery values of actual samples were in the range of 83.9%–107.0% with relative standard deviations (RSDs) of 1.63–4.44%. The quantification limits of the seven phthalates were 3.20 to 13.61 ng mL −1 . Thus, the overall experimental results revealed the promise of deep eutectic solvent (DES) for support in determining phthalate acid esters (PAEs). Therefore, this method could be used for the determination of seven phthalate acid esters in packaged milk samples.
A sensitive method based on the use of green deep eutectic solvents (DESs) was designed for the determination of bisphenol-A, bisphenol-AF, tetrabromobisphenol-A and 4-tert.-octylphenol followed by HPLC. This method takes advantage of magnetic solid-phase extraction purification and acid-base induced DES liquid-liquid microextraction. The Mg(II)-Al(III) layered double hydroxide-coated magnetic nanoparticles were selected to purify samples. The DESs were systematically prepared by a range of medium-chain saturated fatty acids (C 8 -C 12 ) and D,L-menthol. The melting point and the extraction efficiency of phenolic compounds were adjusted by changing the carbon chain length of fatty acid in suitable proportions. Acid-base induction significantly improves the extraction efficiency. The method has lower limits of detection ranging from 6 to 11 ng L −1 , good linearity (0.05–500 μg L −1 ) and high enrichment factors (86–91). The method was successfully applied for the determination of four phenolic compounds in beverage samples. The recoveries ranged from 84.4 to 101.3%.
Schematic representation of the extraction of four phenolic compounds by medium chain (C 8 -C 12 ) fatty acid-based eutectic solvent (DES) through acid-base-induction.
危险品化学品经营许可证（带存储）