Following publication of the original article,1 it came to the authors’ attention that there is an error in the Supporting Information (SI) file.
The words, “benzoic acid,” were inadvertently included in the third paragraph of the second page of the Supporting Information. Thus, this paragraph should be replaced with the following.
Preparation of Free-base and Monoprotonated Standards: Propylene glycol (PG) and glycerol (GL) were combined in a molar ratio of 54:46 (as determined by NMR), with a nicotine concentration of 24 mg/mL. Aliquots were independently combined with acid (acetic acid, 5:1 nicotine, by mol) and base (tert-butylamine, 1:1 nicotine, by mol) to produce monoprotonated and free-base (unprotonated) nicotine. Other acids tested included chloroacetic acid, dichloroacetic acid, trichloroacetic acid, and hydrochloric acid, but these caused diprotonation of the nicotine and so were not used for the preparation of monoprotonated nicotine standard solutions in PG/GL mixtures.
The authors apologize for this error.
References
- Duell A. K.; Pankow J. F.; Peyton D. H. (2018) Free-Base Nicotine Determination in Electronic Cigarette Liquids by 1H NMR Spectroscopy. Chem. Res. Toxicol. 31, 431–434. 10.1021/acs.chemrestox.8b00097. [DOI] [PMC free article] [PubMed] [Google Scholar]