In this study, a dispersive solid phase extraction method was combined with solidification of floating organic drop–liquid–liquid microextraction based on in situ synthesis of deep eutectic solvent. It was used for the extraction of some phytosterols from edible oil samples. The extracted analytes were quantified by gas chromatography–mass spectrometry. In this procedure, the sample lipids are saponified with sodium hydroxide and then the analytes are adsorbed onto an octadecylsilane sorbent. After that the analytes are desorbed from the sorbent with ethanol as an elution solvent and the eluant is diluted with deionized water to obtain a homogenous solution. Then, a few amounts of choline chloride and n-butyric acid are dissolved in the solution and transferred into a water batch adjusted at 75 ⁰C for 5 min. During this period Choline chloride and n-butyric acid form a deep eutectic solvent (extraction solvent) dispersed in whole parts of the solution. The obtained cloudy solution is placed into an ice bath. The extraction solvent is collected and solidified on the top of the solution. Finally, it is removed and allows melted at room temperature and an aliquat of the solution is injected into the separation system. Validation of the method showed that limits of detection and quantification were in the ranges of 0.52–1.6 and 1.7–5.6 ng mL^–1, respectively. Enrichment factors and extraction recoveries of the analytes ranged from 312 to 375 and 75–90%, respectively. The method had a proper percision with relative standard deviations less than ≤8.2% for intra– (n = 6) and inter–day (n = 6) precisions at a concentration of 15 ng mL^–1 of each analyte. Finally the method was successfully used for determination of the analytes in some edible oil samples.

本研究基于原位合成深层共晶溶剂，将分散固相萃取方法与漂浮有机滴凝固-液-液微萃取相结合。用于从食用油样品中提取某些植物甾醇。通过气相色谱-质谱法对提取的分析物进行定量。在此过程中，样品脂质用氢氧化钠皂化，然后分析物吸附到十八烷基硅烷吸附剂上。然后用乙醇作为洗脱溶剂将分析物从吸附剂上解吸，并用去离子水稀释洗脱液以获得均匀溶液。然后，将少量氯化胆碱和正丁酸溶解在溶液中，并转移到调节至75℃的水浴中5分钟。在此期间，氯化胆碱和正丁酸形成分散在整个溶液中的低共熔溶剂（萃取溶剂）。将获得的混浊溶液放入冰浴中。收集萃取溶剂并在溶液顶部固化。最后，将其取出并在室温下熔化，并将溶液的等分液注入分离系统中。该方法的验证表明，检测限和定量限分别在 0.52–1.6 和 1.7–5.6 ng mL ^–1范围内。分析物的富集因子和提取回收率分别为 312 至 375 和 75-90%。该方法具有适当的精密度，每种分析物浓度为 15 ng mL ^–1时，日内 ( n = 6) 和日间 ( n = 6) 精密度的相对标准偏差小于 ≤8.2%。 最终该方法成功用于部分食用油样品中分析物的测定。