Following the 2016 deeming of cigars by the Food and Drug Administration (FDA), there has been an increased interest in cigar science, including ways to accurately measure the harmful and potentially harmful constituents (HPHCs) found within mainstream cigar smoke. Included in this list are various carbonyls including formaldehyde, acetaldehyde, acrolein, and crotonaldehyde. For ease of analysis, carbonyls are traditionally trapped in an acidic DNPH solution to convert the carbonyls to their respective hydrazone adducts. During the analysis of mainstream cigar smoke for carbonyls, it was observed that following sample preparation, the levels of formaldehyde in select cigars would continue to increase over time with a % increase in the relative response of ~ 50 % to 80 % over 17 hours. In the production of cigars, glycerin is typically added as a humectant and previous work has shown that under the correct conditions, glycerin can contribute to the creation of formaldehyde through oxidation and subsequent retro aldol reaction. This has led us to suspect that high levels of glycerin in some cigars may contribute to the increase in observed formaldehyde levels under the sample conditions similar to CORESTA Recommended Method (CRM) 74. To examine this, six aliquots of glycerin-d8 were mixed with DNPH trapping solution, three of which were then quenched with pyridine and the other three were not. All six samples were repeatedly injected overnight using an LCMS and monitored for the formation of formaldehyde-d2-DNPH. Over 12 hours, there was a steady rise in the observed levels of formaldehyde-d2-DNPH in samples which were quenched when compared to unquenched samples (no added pyridine), which remained relatively constant. Overall, there was a three-fold increase in the levels of formaldehyde-d2-DNPH produced in quenched samples as opposed to unquenched samples. Because of this, it is recommended that when assessing samples with a high glycerin content, they be analyzed as quickly as possible to mitigate the overall effect of the production of formaldehyde from glycerin.