The comprehensive determination of fatty acids without derivatization, including short-chain fatty acids (SCFAs), medium-chain fatty acids (MCFAs) and long-chain fatty acids (LCFAs), is a big challenge but powerful for lipidomics in biology, food, and environment. Herein, the dual mode unity solid-phase microextraction (DMU-SPME) combined with gas chromatography-flame ionization detector (GC-FID) or mass spectrometry (MS) was proposed as a powerful method for the determination of comprehensive free fatty acids in real samples. Under the optimized DMU-SPME conditions, the proposed method has good linearity (R 2 ≥ 0.994) and low limits of determination (0.01–0.14 mg/L). In the stability analysis, the intra-day relative standard deviation was 1.39–12.43 %, and the inter-day relative standard deviation was 2.84–10.79 %. The recoveries of selected 10 fatty acids in real samples ranged from 90.18 % to 110.75 %, indicating that the method has good accuracy. Fatty acids ranging from C2 to C22 were detected in real samples by the untargeted determination method of DMU-SPME combined with gas chromatography-mass spectrometry (GC–MS). The DMU-SPME method proposed in this study can be used for lipid metabolism analysis and free fatty acid determination in the fields of biology, food, and environment.
The dual mode unity solid-phase microextraction (DMU-SPME) was evaluated against traditional solvent-based methods, including solvent-assisted flavor evaporation (SAFE) and simultaneous distillation extraction (SDE), to explore its potential as an alternative. Compared to SAFE and SDE, DMU-SPME is a green extraction technology for volatile organic compounds. The results demonstrated that DMU-SPME significantly outperformed both SAFE and SDE in extracting medium-volatility compounds (retention time of 20–40 min), identifying 55 unique volatiles. With the exception of hydrocarbons, DMU-SPME exhibited superior extraction efficiency and significantly better stability compared to both SAFE and SDE methods. Thus, DMU-SPME proves to be a promising alternative for the comprehensive extraction of volatile organic compounds.
危险品化学品经营许可证（带存储）