application of high-Resolution Mass Spectrometry and a Theoretical Model to the quantification of Multifunctional Carbonyls and Organic acids in e-Cigarette aerosol.

Introduction:
This article, published in Environmental Science and Technology, discusses the chemical composition of e-cigarette aerosols and the use of high-resolution mass spectrometry (hRMS) for the identification and quantification of carbonyl compounds in e-cigarette aerosols. The study uses a theoretical model to calculate the relative electrospray ionization sensitivities of hydrazones of organic acids and carbonyls with 2,4-dinitrophenylhydrazine (2,4-DNPh) and applies this method to quantify the concentration of various carbonyl compounds in the aerosol of e-cigarettes. The study also uses collision-induced dissociation (CID) multistage tandem MS (MSn) to confirm the chemical structures of the carbonyl compounds.

Key Points:

* The study used e-cigarettes with Classic Tobacco flavor and collected e-cigarette aerosols through 2,4-DNPh cartridges and 47 mm polytetra fluoroethylene filters.
* The e-cigarette aerosol was analyzed using hRMS and tandem MSn to identify and quantify carbonyl compounds in the aerosol.
* The theoretical model was used to calculate the relative electrospray ionization sensitivities of hydrazones of organic acids and carbonyls with 2,4-DNPh, which enabled quantification of carbonyl compounds in the absence of chemical standards.
* The study quantified five simple carbonyls, six hydroxycarbonyls, four dicarbonyls, three acids, and one phenolic carbonyl in the e-cigarette aerosol.
* hydroxycarbonyls were found to be just as important as simple carbonyls to the composition of the e-cigarette aerosol.
* The study suggests that the thermal degradation of e-liquid solvents propylene glycol and glycerol often generates multifunctional carbonyls that are challenging to quantify because of unavailability of standards.
* The study emphasizes the need for more research on the chemistry and toxicology of the complex product formation in e-cigarette aerosols.

Main Message:
The study highlights the importance of using high-resolution mass spectrometry and a theoretical model for the quantification of carbonyl compounds in e-cigarette aerosols, especially in the absence of chemical standards. The study also underscores the need for further research on the chemistry and toxicology of e-cigarette aerosols, particularly the formation of multifunctional carbonyls and their potential health effects. The findings of this study have important implications for the regulation of e-cigarettes and the assessment of their potential health risks.

Li Y, Burns aE, Burke GJP, et al. application of high-Resolution Mass Spectrometry and a Theoretical Model to the quantification of Multifunctional Carbonyls and Organic acids in e-Cigarette aerosol. Environmental science & technology. 2020;54(9):5640-5650. doi:10.1021/acs.est.9b07387