Non-targeted screening of extractables and leachables in e-cigarettes using a Single Platform UPLC-APGC-QTOF-MS
Characterization of extractables and leachables is essential for ensuring the safety, quality and efficacy of inhalation tobacco products such as e-cigarettes. The initial step for characterizing extractables from e-cigarettes involves targeted screening, i.e., testing the extracts for known impurities. This is a well-established process that can be performed using analytical techniques such as GC-MS and LC-MS/MS. However the final extracts of e-liquids, refill cartridges and e-cigarette aerosol may have impurities present from the starting materials and other packaging and device components that need to be further evaluated.
In this study, the various components of an e-cigarette (end caps, mouth piece, gauze, heating element and flavor formulation) were extracted separately and subjected to a non-targeted high resolution screening using both ultra-performance liquid chromatography (UPLC) and atmospheric pressure gas chromatography (APGC) analysis on a single QTOF-MS platform. MS and MS/MS data was acquired using alternating low and high collision energy states (MSE) across the full analytical mass range. The data from sample extracts was compared to reagent blank to determine the differences and potential extractables.
Both LC and GC acquisition and data processing were handled on a single instrument platform. The first step in ensuring that the compounds identified in extractables profile do not pose any toxicological risks to the consumer is to identify and quantify the extractables. Common plasticizer (dibutyl phthalate), stabilizing agent (4-methyl benzophenone) and few polymer additives were identified in the e-cigarette component extracts by matching accurate mass precursor and fragment ions, retention time and isotopic patterns against a known library of extractables and leachables. This application demonstrates how non-targeted screening using LC and GC workflows can be adopted on a single high resolution mass spectrometry (HRMS) and software platform for extractable and leachable testing in e-cigarettes.