Table 2. Analytical strategies for butyric acid by sample type

Sample type Main analytical challenges Relatively suitable methods Key considerations References
Biological samples (feces, plasma, urine, saliva) Low concentration, complex matrices, limited detection sensitivity GC-based quantification, LC-MS/MS as a complement, derivatization-assisted methods Optimize pretreatment, use internal standards, ensure low detection limits Chen and Lifschitz, 1989; García-Villalba et al., 2012; Kim et al., 2015; Mahdi et al., 2024; Stø et al., 2022
Food and fermentation samples (dairy products, fermentation broths, culture media) Interference from lipids, proteins, flavor compounds, and variable production levels GC for routine analysis, HPLC as a complementary approach Reproducibility, removal of interfering substances, standardized pretreatment Aiello et al., 2023; Danudol and Judprasong, 2022; Hadinia et al., 2022; Shelley et al., 1963
Process and environmental samples Volatile loss, separation of homologous fatty acids, and field applicability GC or combined GC/LC approaches Rapid handling, sealed conditions, cost effectiveness Ferreira et al., 2016; Koper and Grabarczyk, 2014; Zeng et al., 2013
Complex mixed matrices Multiple co-eluting compounds and difficulty in ensuring selectivity LC-MS/MS, HRMS High-resolution separation, simultaneous identification and quantification, high instrument cost Chen et al., 2021; Mosen et al., 2021
Simple high-concentration samples Analysis itself is relatively straightforward, but throughput matters GC / GC-MS Fast routine analysis, cost efficiency, minimal complexity Jiang et al., 2025; Kim et al., 2019; Zhao et al., 2006