Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Samples of donated commercially available nicotine samples_
| Nicotine Source | Identifier | Supplier/Manufacturer | Description |
|---|---|---|---|
| Tobacco-derived nicotine (TDN) | TDN-1 | Siegfried | Tobacco-derived S-nicotine |
| TDN-2 | Nicotine River | Tobacco-derived S-nicotine (in propylene glycol / 100 mg/mL / freebase) | |
| TDN-3 | Siegfried | Tobacco-based S-nicotine (TDN) Polacrilex (20%) | |
| Synthetic nicotine (SyN) | SyN-1 | Next Generation Labs (NGL) | Synthetic S-nicotine |
| SyN-2 | Next Generation Labs | Synthetic R-nicotine | |
| SyN-3 | Next Generation Labs | Synthetic R/S-nicotine | |
| SyN-4 | Nicobrand | Synthetic S-nicotine | |
| SyN-5 | Tobacco Technology, Inc. | Synthetic S-nicotine salt (in propylene glycol) 100 mg/mL | |
| SyN-6 | Nicotine River | Synthetic S-nicotine (in propylene glycol / 100 mg/mL / freebase) | |
| SyN-7 | Nicotine River | Synthetic S-nicotine salt (in propylene glycol / 100 mg/mL / freebase) | |
| SyN-8 | AlChem (NicSelect) | S-Synthetic nicotine | |
Chromatographic conditions employed for the analysis of selected secondary alkaloids_
| Injection port temperature | 260 °C |
| Purge valve | 40 mL/min after 1 min |
| Septum purge | 3 mL/min |
| Purge time | 1 min |
| Total flow | 44 mL/min |
| Constant flow | 1 mL/min |
| Injection volume | 1μL, splitless |
| Column oven initial temperature | 40 °C |
| Column oven initial time | 3 min |
| Column oven ramp rate | 20 °C/min |
| Column oven final temperature | 250°C |
| Column oven final time | 5 min |
| MSD transfer line temperature | 260 °C |
Results of R- and S-nicotine and R- and S-nornicotine in commercial samples_
| Nicotine source | Identifier | Supplier/Manufacturer | Description | S-nicotine (counts) (%) | R-nicotine (counts) (%) | Presence of nornicotine | S-nornicotine (counts) (%) | R-nornicotine (counts) (%) | Description correct |
|---|---|---|---|---|---|---|---|---|---|
| Tobacco-Derived Nicotine (TDN) | TDN-1 | Siegfried | S-Tobacco-derived Nicotine | 29,564,334 (99.3%) | 204,633 (0.7%) | Yes | 35,580 (100.0%) | 0 (0%) | Equivocal |
| TDN-2 | Nicotine River | S-Tobacco-derived Nicotine (in Propylene Glycol / 100 mg/mL / freebase) = PurNic Nicotine 100 mg/mL Propylene Glycol | 136,661 (99.3%) | 951 (0.7%) | No | - - | ND | Equivocal | |
| TDN-3 | Siegfried | S-Tobacco-derived Nicotine (TDN) Polacrilex (20%) | 165,127 (99.6%) | 624 (0.4%) | Yes | 2,941 (100.0%) | 0 (0%) | Equivocal | |
| Synthetic Nicotine (SyN) | SyN-1 | Next Generation Labs (NGL) | S-Synthetic Nicotine | 887,787 (98.1%) | 17,532 (1.9%) | Yes | 22,530 (100.0%) | 0 (0%) | Yes |
| SyN-2 | Next Generation Labs | R-Synthetic Nicotine | 34,459 (3.1%) | 1,064,770 (96.9%) | No | - - | ND | Equivocal | |
| SyN-3 | Next Generation Labs | R/S-Synthetic Nicotine | 466,687 (52.5%) | 421,496 (47.5%) | Yes | 11,753 (86.9%) | 1,764 (13.1%) | Equivocal | |
| SyN-4 | Nicobrand | S-Synthetic Nicotine | 1167,264 (99.3%) | 8,798 (0.7%) | Yes | 13,352 (93.4%) | 938 (6.6%) | Yes | |
| SyN-5 | Tobacco Technology, Inc. | S-Synthetic Nicotine (in propylene glycol) 100 mg/mL | 1,098,405 (99.8%) | 2,702 (0.2%) | Yes | 18,287 (82.1%) | 3,982 (17.9%) | Equivocal | |
| SyN-6 | Nicotine River | S-Synthetic Nicotine (in propylene glycol / 100 mg/mL / freebase) = SyNic tobacco-free nicotine propylene glycol 100 mg/mL | 152,379 (100.0%) | 0 (0%) | Yes | 2,359 (100.0%) | 0 (0%) | Yes | |
| SyN-7 | Nicotine River | S-Synthetic Nicotine Salt (in propylene glycol / 100 mg/ml / freebase) = SyNic tobacco-free nicotine smooth salt propylene glycol-derived 100 mg/mL | 126,285 (100.0%) | 0 (0%) | Yes | 1,400 (100.0%) | 0 (0%) | Yes | |
| SyN-8 | AlChem (NicSelect) | S-Synthetic Nicotine | 1,557,635 (99.2%) | 12,931 (0.8%) | Yes | 215,195 (92.8%) | 16,705 (7.2%) | Yes |
Distribution of R- and S-nicotine and R- and S-nornicotine in reference cigarette tobacco and types of Nicotiana tabacum L_ (20, 21)_
| Tobacco | Nicotine | Nornicotine | ||
|---|---|---|---|---|
| S (%) | R (%) | S (%) | R (%) | |
| 1R1 tobacco | > 97.5 | < 2.5 | 62 | 38 |
| 2R1 tobacco | > 97.5 | < 2.5 | 68 | 32 |
| 1R4F tobacco | > 97.5 | < 2.5 | 67 | 33 |
| 1R3F tobacco | > 97.5 | < 2.5 | 65 | 35 |
| 2R1F tobacco | > 97.2 | < 2.7 | 62 | 38 |
| 1R5F tobacco | > 97.5 | < 2.5 | 74 | 26 |
| Cherry Red tobacco | > 97.5 | < 2.5 | 95 | 5 |
| Flue-cured tobacco | > 97.5 | < 2.5 | 57 | 43 |
| Burley tobacco | > 97.5 | < 2.5 | 82 | 18 |
| Oriental tobacco | > 97.5 | < 2.5 | 80 | 20 |
| Average | 97.5 | 2.5 | 71 | 29 |
| Standard deviation | 0 | 0 | 11 | 11 |
Tobacco-derived nicotine and synthetic nicotine e-cigarettes in current study_
| Claimed nicotine source | Identifier | Description |
|---|---|---|
| Tobacco-derived nicotine (TDN) | TDN ECig-1 | N-JOY Daily Rich Tobacco - 45mg E-Juice |
| TDN ECig-2 | Tropical Mango 5% Nicotine salt NEW Boss Bar | |
| TDN ECig-3 | blu Polar Mint | |
| Synthetic nicotine (SyN) | SyN Ecig-1 | Mr. Fog Max 1000puffs - Blueberry Raspberry Lemon |
| SyN Ecig-2 | Helix Bar Max 1500 Puffs Disposable Vaporizer - 5.6ML - Strawberry Iced - 50mg | |
| SyN Ecig-3 | VaporLax - Cool Mint by Draco | |
| SyN Ecig-4 | Ignite Vape Pen - Blue Razz Ice | |
| SyN Ecig-5 | Fuze Disposable Vape (1500 Puffs) Adjustable Air Flow - Banana Mango (New Zush 1500 Puffs) | |
| SyN Ecig-6 | Electric Tobacconist Dinner Lady - Citrus Ice Disposable - 50mg | |
| SyN Ecig-7 | GoBoosted Peach Ice (20mg/mL) | |
| SyN Ecig-8 | GoBoosted Blackcurrant Lychee (20mg/mL) | |
Selected ions, component retention times, and approximate detection limits employed in the analysis of selected secondary alkaloids_
| Compound | SIM ions | Retention time (min) | Approximate concentration (ng/mL) |
|---|---|---|---|
| Anatabine | 160, 131 | 12.73 | 20 |
| Anabasine | 162, 133 | 12.06 | 20 |
| Nornicotine | 146, 118 | 12.01 | 20 |
Nicotine and secondary tobacco alkaloid standards_
| Standard number | Standardsa | Source |
|---|---|---|
| 1 | R/S-nicotine | Millipore Sigma |
| 2 | S-nicotine | Millipore Sigma |
| 3 | R-nicotine | TRCb |
| 4 | R/S-nornicotine | Millipore Sigma |
| 5 | R-nornicotine | TRC |
Results of the chiral SCF analysis for the resolution of R- and S-nicotine and R- and S-nornicotine (8)_
| Analytical standard | Source | Resolution of isomers | Presence of nornicotine by chiral-SFC with DAD-UV on a Chiralpak IG-3 column | Presence of nornicotine by GC/SIM/MS |
|---|---|---|---|---|
| R/S-nicotine | Millipore Sigma | Complete | No | Yes |
| S-nicotine | Millipore Sigma | -- | No | Yes |
| R-nicotine | TRC* | -- | No | Yes |
| R/S-nornicotine | Millipore Sigma | Complete | Yes | Yes |
| R-nornicotine | TRC* | -- | Yes | Yes |
Results of R- and S-nicotine and R- and S-nornicotine in e-liquids of e-cigarettes samples_
| Claimed nicotine source | Identifier | Supplier/Manufacturer | Description | S-nicotine (counts) (%) | R-nicotine (counts) (%) | Presence of nornicotine | S-nornicotine (counts) (%) | R-nornicotine (counts) (%) | Description correct |
|---|---|---|---|---|---|---|---|---|---|
| Tobacco-Derived (TDN) | TDN Ecig-1 | N-Joy by Electric Tobacconist (www.electrictobacconist.com) | N-JOY Daily Rich Tobacco - 45 mg | 560,710 (99.7%) | 1,606 (0.3%) | Yes | 4,969 (83.6%) | 972 (16.4%) | Equivocal |
| TDN Ecig-2 | Puff Bar (www.vaporboss.com) | Tropical Mango 5% Nicotine salt NEW Boss Bar | 507,066 (99.6%) | 1,060 (0.4%) | Yes | 2,363 (100%) | 0 (0%) | Equivocal | |
| TDN Ecig-3 | blu by ITG - Electric Tobacconist (www.electrictobacconist.com) | blu Polar Mint | 253,560 (99.3%) | 1,670 (0.7%) | Yes | 4,344 (100%) | 0 (0%) | Equivocal | |
| Synthetic Nicotine (SyN) | SyN Ecig-1 | Mr. Fog (www.mrfog.ca) | Mr. Fog Max 1000 Puffs - Blueberry Raspberry Lemon | 616,609 (99.4%) | 3,939 (0.6%) | Yes | 18,038 (100%) | 0 (0%) | Equivocal |
| SyN Ecig-2 | Helix Bar | Helix Bar Max 1500 Puffs Disposable Vaporizer - 5.6 mL - Strawberry Iced - 50 mg | 2,085,599 (99.6%) | 8,206 (0.4%) | Yes | 12,231 (100%) | 0 (0%) | Equivocal | |
| SyN Ecig-3 | Vapor Lax Mi-One Brands (www.mipod.com) - Draco | Vapor Lax - Cool Mint by Draco | 1,124,149 (100%) | 0 (0%) | Yes | 9,714 (83.7%) | 1,886 (16.3%) | Equivocal | |
| SyN Ecig-4 | Ignite Pen (IgniteVape.Co) | Vape Pen - Blue Razz Ice | 1,066,619 (73.6%) | 382,226 (26.4%) | Yes | 11,565 (100%) | 0 (0%) | Uncertain | |
| SyN Ecig-5 | Fuze (www.vaporboss.com) | Fuze Disposable Vape (1500 Puffs) Adjustable Air Flow - Banana Mango (New Zush 1500 Puffs) | 711,809 (99.9%) | 680 (0.1%) | Yes | 8,355 (69.8%) | 3,617 (30.2%) | Uncertain | |
| SyN Ecig-6 | Electric Tobacconist (www.electrictobacconist.com) | Dinner Lady - Citrus Ice Disposable - 50 mg | 390,955 (52.4%) | 354,824 (47.6%) | Yes | 0 (0%) | 0 (0%) | Equivocal | |
| SyN Ecig-7 | Boosted (GoBoosted.com) | Peach Ice (20 mg/mL) | 854,080 (100%) | 0 (0%) | Yes | 12,531 (100%) | 0 (0%) | Equivocal | |
| SyN Ecig-8 | Boosted Bar (GoBoosted.com) | Blackcurrant Lychee (20 mg/mL) | 1,212,558 (100%) | 0 (0%) | Yes | 7,077 (100%) | 0 (0%) | Equivocal |