建立了植物油脂中31种脂肪酸成分的全二维气相色谱-四极杆质谱(GC×GC-qMS)分析方法.样品经甲酯化衍生后,以DB-1柱(30 m×0.25 mm ×0.25 μm)作为一维柱、DB-Wax柱(3.2m×0.1 mm×0.1 μm)作为二维柱组成柱系统进行分离,在调制周期为3.5s、四极杆质量扫描范围为m/z 40～350的条件下,植物油脂中31种脂肪酸成分可以在50 min内得到准确和灵敏的检测.将本方法应用于实际样品的分析,灵敏度较传统的气相色谱-质谱法提高了100倍以上,一些植物油中微量的脂肪酸成分也因此被检出.该研究不仅为植物油中脂肪酸成分的分析提供了新的技术手段,同时对于确保食用植物油的质量安全、消除食用植物油的掺假伪劣等均有重要意义.%Comprehensive two-dimensional gas chromatography with quadropole mass spectrometry (GC xGC-qMS) was applied to the detection of 31 fatty acids in vegetable oils. The sets of columns, modulation period, scan range of quadropole mass spectrometer were optimized. The results demonstrated that the separation was achieved in 50 min with the column set of DB-1 (30 m xO. 25 mm xO. 25 (jim) as the 1st column and DB-Wax (3. 2 m xO. 1 mm x 0. 1 (j,m) as the 2nd column. All fatty acids were accurately and sensitively determined while the modulation period was 3. 5 s and the scan range of quadropole MS was m/z 40 -350. Most of the fatty acids were identified by NIST library spectra search, the other fatty acid isomers were identified by single standard injection analysis. When applying this method to the real vegetable oil samples, not only the sensitivities were 100 times higher than those obtained with GC-qMS methods, but also some minor fatty acids were identified. This work suggested a new technical approach in analyzing fatty acid components in vegetable oils, which is meaningful to prohibit adulteration and ensuring the quality safety of edible vegetable oils.
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