A Rapid QuEChERS-GC-MS Assay for Linalool and Alpha-ionone Determinations in Tea

Objective An assay to detect the aromatic linalool and alpha-ionone in tea applying gas chromatography-mass spectrometry (GC-MS) was developed.

Method Tea samples were firstly extracted by acetonitrile to collect the supernatant for the QuEChERS purification on a column containing 200 mg of PSA, 200 mg of CB, and 400 mg of anhydrous sodium sulfate prior to GC-MS analysis. Under the ion monitoring mode (SIM), aromatic compounds were quantifiably determined with external standards.

Result The assay detection limit on linalool was 0.020 mg·kg⁻¹ and that on alpha-ionone 0.004 mg·kg⁻¹; while the quantification limit was 0.080 mg·kg⁻¹ on linalool and 0.010 mg·kg⁻¹ on alpha-ionone. The measurement curves on the two aromatherapy substances were linear in concentrations of 5.0-2000.0 μg·L⁻¹ with a greater than 0.999 correlation coefficient (R²). On the blank control sample of tea spiked with 5.0, 10.0, and 1000.0 μg·L⁻¹ of standard linalool and alpha-ionone, the assay showed an average recovery of 88.23%-106.11% with a relative standard deviation (RSD) of 1.98%-3.25% (n=6).

Conclusion The newly developed method was rapid with a running time of only 16.8 m and highly reproducible, accurate, and sensitive results. It was deemed applicable for rapid detection of linalool and alpha-ionone in tea.