Liquid chromatography-tandem mass spectrometry method for measuring vitamin E acetate in bronchoalveolar lavage fluid.

Introduction:
This text describes a study that developed and validated a method for detecting vitamin E acetate (VEa) in bronchoalveolar lavage (BaL) fluid using isotope-dilution liquid chromatography coupled with tandem mass spectrometry. The study aimed to measure VEa in BaL fluid as a way to better understand the accumulation and health effects of inhaled VEa in the lungs of people who use e-cigarettes or vaping products (EVPs).

Key Points:

* The study found that the method is accurate, selective, and sensitive, with mean recoveries higher than 90%, coefficients of variation ranging from 1.5% to 4.5%, and a limit of detection of 1.10 ng/mL.
* Calibration curves were linear (R2 > 0.99) and the linear range and detection limit of the method were adequate for identifying VEa in 48 of 51 BaL fluid samples collected from people with lung injury resulting from EVP use.
* The method was used to analyze BaL fluid samples from 51 case-related EVPs and VEa was detected in 48 of the 51 (94%) case patients samples analyzed. Concentrations ranged from "non-detect" to 19,900 ng/mL.
* VEa does not occur naturally and has been added to vaping liquids to lower production costs while maintaining the golden color and viscous appearance of pure ThC oil.
* VEa has been associated with lung injury cases and mice exposed to vaped VEa develop a pattern of lung injury that closely resembles that seen in EV aLI patients.
* BaL fluid was already being collected from some EV aLI patients to assess for other underlying causes of illness, making it a convenient sample to measure VEa in.
* The study helped save lives by stopping the EV aLI outbreak and establishes LC-MS/MS analysis of BaL fluid as a strategy for evaluating inhaled toxicants.

Main Message:
The study describes the development and validation of a method for detecting vitamin E acetate in bronchoalveolar lavage fluid using isotope-dilution liquid chromatography coupled with tandem mass spectrometry. The method was used to analyze BaL fluid samples from 51 case-related EVPs and VEa was detected in 48 of the 51 (94%) case patients samples analyzed. The study helped save lives by stopping the EV aLI outbreak and establishes LC-MS/MS analysis of BaL fluid as a strategy for evaluating inhaled toxicants. This method could be useful for regulatory agencies to monitor and regulate the use of VEa in vaping liquids.

Morel Espinosa M, Blount BC, Valentin-Blasini L. Liquid chromatography-tandem mass spectrometry method for measuring vitamin E acetate in bronchoalveolar lavage fluid. Journal of chromatography B, analytical technologies in the biomedical and life sciences. 2021;1171:122607. doi:10.1016/j.jchromb.2021.122607