Table 1.
List of flavoring chemicals and their characteristics.
| E-liquid Flavoring Chemical | Flavor Profile | H2O Solubility (mM) * | Chemical Class | Molecular Structure |
|---|---|---|---|---|
| 2,3,5-Trimethylpyrazine | Cocoa; Nutty | 2.6 × 102 | Methyl, pyrazine |
|
| 2,3-Butanedione | Buttery; Sweet | 4.0 × 103 | acetyl, ketone |
|
| 2,3-Heptanedione | Buttery; Dairy | 2.6 × 102 | acetyl, ketone |
|
| 2,3-Hexanedione | Creamy; Fruity | 8.7 × 102 | acetyl, ketone |
|
| 2,3-Pentanedione | Buttery; Caramel | 2.8 × 103 | acetyl, ketone |
|
| 2-Acetylpyrazine | Bready; Nutty | 8.9 × 103 | acetyl, pyrazine |
|
| Acetaldehyde | Tart; Green Apple | 2.3 × 104 | acetyl, aldehyde |
|
| Acetoin | Creamy; Dairy | 1.1 × 104 | acetyl, hydroxyl |
|
| Alpha-pinene [(−)-α-pinene] | Cedarwood, Pine | 1.8 × 10−4 | isoprene, methyl |
|
| Benzyl Alcohol | Cherry; Almond | 2.1 × 103 | benzene, hydroxyl |
|
| Butyraldehyde | Cocoa; Green | 9.8 × 102 | aldehyde |
|
| Cinnamaldehyde | Cinnamon; Spice | 1.1 × 100 | benzene, aldehyde |
|
| Decanal | Citrus; Orange peel | 8.7 × 10−2 | aldehyde |
|
| DL-Menthol | Menthol; Minty | 2.9 × 100 | isoprene, hydroxyl |
|
| Ethyl Acetate | Fruity; Grape | 9.1 × 102 | ester |
|
| Ethyl Butyrate | Fruity; Apple | 5.3 × 101 | ester |
|
| Ethyl Maltol | Sweet; Sugary | 2.1 × 102 | hydroxyl, pyrone |
|
| Eugenol | Clove; Spice | 2.7 × 101 | hydroxyl, methoxy, benzene |
|
| Furfural | Bready; Nutty | 8.0 × 102 | aldehyde, furan |
|
| Hexanal | Fruity; Green | 5.0 × 101 | aldehyde |
|
| Isoamyl Acetate | Fruity; Banana | 1.4 × 101 | ester |
|
| Isopropyl Myristate | Cheesy; Dairy | Insoluble (5.1 × 10−5) | ester |
|
| L-Carvone | Spearmint; Caraway | 8.7 × 100 | isoprene, ketone |
|
| Limonene [(R)-(+)-Limonene] | Citrus; Orange | 1.0 × 10−1 | isoprene, methyl |
|
| Linalool | Lemon; Lavender | 1.0 × 101 | isoprene, hydroxyl |
|
| Methyl Salicylate | Wintergreen; Peppermint | 2.7 × 101 | ester, hydroxyl, benzene |
|
| Nonanal | Green; Lemon | 6.8 × 10−1 | aldehyde |
|
| Propionaldehyde | Floral; Grape | 4.5 × 103 | aldehyde |
|
| Trans-2-Hexen-1-al | Fruity; Green | 7.5 × 101 | aldehyde |
|
| Vanillin | Sweet; Vanilla | 7.2 × 101 | aldehyde, benzene, hydroxyl, methoxy |
|
* Source: USEPA: https://comptox.epa.gov/dashboard/dsstoxdb/results?search=DTXSID1047075#properties (accessed on 23 September 2021). All values are median experimental values where available, otherwise median or average predicted values.