Institute of Food Chemistry (170b), University of Hohenheim, Garbenstrasse 28, D-70599 Stuttgart, Germany.
J Agric Food Chem. 2024 Apr 10;72(14):8247-8256. doi: 10.1021/acs.jafc.3c08324. Epub 2024 Mar 29.
The compound-specific determination of δC values [‰] by gas chromatography interfaced with isotope ratio mass spectrometry (GC-IRMS) is a powerful analytical method to indicate minute but relevant variations in the C/C ratio of sample compounds. In this study, the δC values [‰] of individual sterols were measured in eleven different oils of C, C, and CAM plants ( = 33) by GC-IRMS. For this purpose, a suitable acetylation method was developed for sterols. Nine of the eleven phytosterols identified by GC with mass spectrometry (GC/MS) could be measured by GC-IRMS. The δC values [‰] of individual sterols and squalene of C plant oils were between 3‰ and >16‰ more negative (lighter in carbon) than in C and CAM oils. We also showed that the blending of C oils into C oils (exemplarily conducted with one olive and one corn oil) would be precisely determined by means of the δC value [‰] of β-sitosterol.
通过气相色谱-同位素比质谱联用仪（GC-IRMS）对 δC 值（‰）进行化合物特异性测定，是一种指示样品化合物 C/C 比发生微小但相关变化的有力分析方法。在这项研究中，通过 GC-IRMS 测量了 11 种不同的 C、C 和 CAM 植物油中的单个甾醇的 δC 值（‰）（n = 33）。为此，开发了一种适用于甾醇的乙酰化方法。通过 GC 与质谱联用（GC/MS）鉴定的 11 种植物甾醇中有 9 种可以通过 GC-IRMS 进行测量。C 植物油中个别甾醇和角鲨烯的 δC 值（‰）比 C 和 CAM 油中的更负（碳较轻），范围在 3‰至>16‰之间。我们还表明，通过 β-谷甾醇的 δC 值（‰）可以精确确定 C 油混入 C 油（例如，用橄榄油和玉米油进行混合）的情况。
