Rapid Determination of 6-Methyl-5-hepten-2-one in Fruit with LLE-GC-MS

The volatile compound 6-methyl-5-hepten-2-one (MHO) is an important chemical intermediate and flavor component derived from carotenoid during fruit metabolism, which is important factor impacting consumer-liking. Fruit has complex matrix and is difficult to be purified during MHO analysis. A rapid liquid-liquid extraction-gas chromatography-mass spectrometry (LLE-GC-MS) method was developed for effective determination of MHO in fruit in this study. The calibration curves for MHO showed high linearity in the range of 100-2000 ng/ml with internal standard method. The limit of detection (LOD), limit of quantification (LOQ) were both <100 ng/ml. Real samples of tomato cultivar fruit were analyzed and RSD of biological replicates varied in the range of 2.01% to 12.59%. MHO showed varied content in different tomato fruit tissues of the selected cultivars, in addition to the variation between cultivars. Furthermore, the possible fragmentation patterns were proposed for the main characteristic ions of MHO and internal standard, based on isolation of the fragment ions after the precursor ion underwent splitting at the electron impact ion source. Compared with reported solid-phase microextraction (SPME)-GC-MS method, the validated method was more rapid, precise, accurate and low cost for MHO quantitation.