A simplified method for the analysis of mono-carbonyl compounds in e-cigarette aerosols by LC-MS
Mono-carbonyls (formaldehyde, acetaldehyde, acrolein and crotonaldehyde) are present in e-cigarette aerosols, often at trace levels. In recent years, various methods have been reported for the analysis of these compounds at low levels by LC-MS, LC-MS/MS and GC-MS. Herein we wish to present a simplified and robust LC-MS method we have developed to quantitate mono-carbonyls in e-cigarette aerosols. A UPLC system coupled with a single quadrupole mass spectrometer (Waters Acquity UPLC with QDa detector) has been used for the analysis. Chromatography from traditional smoke sample analysis has been modified to improve the separation of these four analytes from the interferences in sample matrices so that the analysis can be performed with good accuracy without internal standards being used. The new method has been validated with good recoveries (85.5 – 121.6%) on e-cigarette aerosols. The overall calibration range is 2 to 400 ng/mL for all four analytes, which covers most of the commercial e-cigarette samples tested without dilution of the sample solutions needed. The LOQ of the method is 2.9 ng/puff for all four analytes. The new method is robust and has been used for the analysis of 30 to 70 e-cigarette samples per day over a period of multiple weeks without any extra instrument maintenance needed.