FDA’s Premarket Tobacco Product Application (PMTA) draft guidance for Electronic Nicotine Delivery Systems (ENDS) recommends analysis of four carbonyls in e-liquids and aerosols - Formaldehyde, Acetaldehyde, Acrolein and Crotonaldhyde. There are two CORESTA recommended methods (CRM) for analysis of carbonyls; CRM No. 74 for mainstream cigarette smoke and CRM No. 86 for tobacco and tobacco products. However, there is currently no CRM for measuring carbonyls in e-vapor products. Carbonyls in e-vapor products are typically lower in concentration compared to those in mainstream smoke. This requires additional method optimization to ensure that the derivatization efficiency and stability of the analytes during the collection process are acceptable to accurately quantify the lower levels of carbonyls. The specific aim of this study was to evaluate the impact of the DNPH type and concentration, solvents, acid type and pH on the derivatization efficiency for e-liquids. Since the inherent levels of these carbonyls in aerosols from e-vapor products are extremely low and inconsistent, we used fortified e-liquid samples to monitor the recovery. We also evaluated the impact of e-liquid composition on derivatization efficiency. Acrolein can react multiple times with DNPH forming a polyderivatized hydrazone, which can accout for low recoveries. Our results demonstrate that the acidity of the solution has a significant impact on the derivatization rate, with low pH resulting in rapid decrease in acrolein-DNPH complex. Using buffered solutions to control the pH, coupled with optimizing the concentration of DNPH and solvent, resulted in an improved method, which provided stable recoveries above 85% for all the carbonyls. The learnings from this work could also be applied to the analysis of carbonyls from other tobacco products.