Abstract:Efficient separation of eight common off-flavor metabolites in cyanobacteria was successfully achieved by optimizing extraction and enrichment conditions such as microwave distillation and solid-phase microextraction, and utilizing comprehensive two-dimensional gas chromatography separation. A detection method for odor metabolites from cyanobacteria in fish meat was established by the quantitative analysis using internal standards with precise mass-to-charge ratios of characteristic ions. The results demonstrated that the eight off-flavor metabolites exhibited good linearity within a concentration range of 0.01 to 100.00 μg/L. The method had detection limits ranging from 0.07 to 3.30 μg/kg and quantification limits ranging from 0.2 to 10.0 μg/kg. The recovery rates ranged from 72.5% to 103.7%, and the relative standard deviations(RSD) were between 2.26% and 14.30%(n=6). Analysis of freshwater fish products revealed the highest concentration of dimethyl trisulfide, geosmin, β-cyclocitral, β-ionone and indole could reach 7.21×102, 3.18, 1.85×102, 94.6, 4.69×102 μg/kg, respectively. This analytical method is accurate, highly sensitive, and exhibits good stability, greatly reducing false positive issues. It can be used as a screening and confirmation method for the presence of cyanobacteria odor metabolites in aquatic products.
