RESUMO
The presence and toxicological risks of synthetic coolants in electronic nicotine delivery systems (ENDS) have not been thoroughly studied. We identified the synthetic coolant menthone 1,2-glycerol ketal (MGK) in a menthol-flavored e-liquid at a concentration of â¼170 µg/mL. We also detected MGK in aerosols resulting from heating the e-liquid with an electronic waterpipe. MGK was initially detected in the e-liquid by two-dimensional gas chromatography-time-of-flight mass spectrometry. To avoid potential analytical artifacts that could result from heating samples in the injection port of the gas chromatograph, quantitation of MGK in the e-liquid was accomplished using a liquid chromatography-tandem mass spectrometry method. Following recent reports identifying other synthetic coolants in e-liquids, these results add knowledge about inhalation exposures from ENDS use and suggest the importance of future research to study the potential inhalation toxicity related to the use of MGK-containing e-liquids in ENDS devices. Furthermore, the results demonstrate the ability to quantify ketals in e-liquids using liquid chromatography methods.