Table 1.
Influence of e-liquid formulation on mass-based aerosol characteristics measured using a low-flow cascade impactor (n = 6 trials/e-liquid).
| E-liquid consumed (μg/puff) | Concentration per puff (μg/cm 3 ) | |||||
|---|---|---|---|---|---|---|
| E-liquid | Mean ±SD | CV (%) | Mean ±SD | CV (%) | MMAD (μm) | GSD |
| 30:70 PG:VG | 3,906 ± 1,233A | 32 | 67.4 ± 21.6A, B, C | 32 | 0.93A, B | 1.43 |
| 30:70 PG:VG w/flavorings | 2,578 ± 451.3A | 18 | 51.0 ± 7.8C | 15 | 0.88B | 1.38 |
| 30:70 PG:VG w/nicotine | 3,272 ± 220.6A | 6.7 | 84.5 ± 22.7A | 27 | 0.86B | 1.36 |
| 70:30 PG:VG | 3,931 ± 1,648A | 42 | 51.7 ± 3.0B, C | 6 | 1.00A | 1.43 |
| 70:30 PG:VG w/flavorings | 3,328 ± 284.7A | 8.5 | 78.8 ± 5.3A, B | 7 | 0.93A, B | 1.36 |
| 70:30 PG:VG w/nicotine | 3,597 ± 560.0A | 16 | 90.3 ± 19.5A | 22 | 0.91A, B | 1.38 |
SD, standard deviation; CV, coefficient of variation; MMAD, mass median aerodynamic diameter; GSD, geometric standard deviation; PG, propylene glycol; VG, vegetable glycerin.
Levels not connected by same letter (A, B, C) are significantly different. For main effects on comparisons of MMADs, the absence of flavoring or nicotine in the humectant significantly increased MMADs of aerosol from e-liquids (p = 0.005). Also, significantly increased MMADs were observed for 70:30 PG:VG compared with aerosol from e-liquids prepared with 30:70 PG:VG (p = 0.017).