Mean comparisons of NNN, NNK, NAT and NAB levels in 227 VP samples by country
| Country | N | Mean | SD | Minimum | Maximum | Df | F | Sig. | |
| NNN | USA | 51 | 17.1 | 21.8 | 0.4 | 125.8 | |||
| Australia | 15 | 0.4 | 0.0 | 0.4 | 0.4 | ||||
| Canada | 9 | 0.6 | 0.5 | 0.4 | 1.4 | ||||
| England | 151 | 0.9 | 2.4 | 0.4 | 22.0 | ||||
| Total | 226 | 4.5 | 12.5 | 0.4 | 125.8 | 3 | 31.66 | P<0.001 | |
| NNK | USA | 51 | 6.6 | 18.0 | 10.4 | 120.8 | |||
| Australia | 15 | 0.7 | 0.1 | 0.7 | 1.1 | ||||
| Canada | 10 | 0.8 | 0.4 | 0.7 | 1.9 | ||||
| England | 151 | 1.7 | 4.6 | 0.5 | 35.9 | ||||
| Total | 227 | 2.7 | 9.5 | 0.4 | 120.8 | 3 | 3.95 | P=0.009 | |
| NAT | USA | 51 | 16.6 | 23.9 | 0.4 | 100.4 | |||
| Australia | 15 | 0.4 | 0.2 | 0.4 | 1.2 | ||||
| Canada | 10 | 0.4 | 0.1 | 0.4 | 0.5 | ||||
| England | 151 | 3.0 | 8.2 | 0.3 | 60.0 | ||||
| Total | 227 | 5.8 | 14.3 | 0.3 | 100.4 | 3 | 15.10 | P<0.001 | |
| NAB | USA | 51 | 4.4 | 4.4 | 0.4 | 45.2 | |||
| Australia | 15 | 0.4 | 0.0 | 0.4 | 0.4 | ||||
| Canada | 10 | 0.4 | 0.0 | 0.4 | 0.4 | ||||
| England | 151 | 0.7 | 1.1 | 0.4 | 10.2 | ||||
| Total | 227 | 1.5 | 4.9 | 0.4 | 45.2 | 3 | 8.32 | P<0.001 |
LOQ for each nitrosamine: NNN: 0.5 ng/mL, NNK: 1.0 ng/mL, NAT: 0.5 ng/mL, NAB: 0.5 ng/mL.
LOQ, limit of quantitation; NAB, N’-nitrosoanabasine; NAT, N’-nitrosoanatabine; NNK, 4-(Methylnitrosamino)−1-(3-pyridyl)−1-butanone; NNN, N’-nitrosonornicotine; VP, vaping product.