Concurrent quantification of Emerging Chemicals of health Concern in e-Cigarette Liquids by high-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Introduction:
This text describes a study that aimed to develop and validate a method for measuring emerging chemicals of concern (ECCs) in e-cigarette liquids using high-performance liquid chromatography coupled with tandem mass spectrometry. The study focused on organophosphate flame retardants (OPFRs), phthalate plasticizers, and tetrabromobisphenol a (TBBPa). The authors evaluated the sample preparation methods, matrix ion suppression, background residuals, and potential carryover, and validated the method by determining the limits of detection, limits of quantitation, dynamic linear ranges, accuracy, and precision.

Key Points:

* The study developed a "dilute-and-shoot" sample preparation method that minimized undesirable errors and deviations observed during SPE cleanup procedures.
* The authors optimized the LC gradient program to minimize system contamination and observed no significant matrix ion suppression.
* The method was validated and found to have low limits of detection and quantitation, wide dynamic linear ranges, and good accuracy and precision.
* The authors applied the method to measure ECCs in 20 e-cigarette refill liquids and detected several compounds in 10-25% of the samples.
* at least one of the analytes was detected in all the samples, and the concentrations for certain analytes were extremely high in some samples.
* The study suggests that this method can be useful to quantify the emerging chemicals of health concern in e-cigarette liquids, thus addressing the information gap pertinent to the safety of e-cigarette products.

Main Message:
The study developed a sensitive, accurate, and precise method for measuring ECCs in e-cigarette liquids, which can provide valuable information for the safety evaluation of e-cigarette products. The detection of several ECCs in e-cigarette refill liquids highlights the need for further research and regulation of these products to ensure public health safety.

Wei B, Goniewicz M, O’Connor RJ. Concurrent quantification of Emerging Chemicals of health Concern in e-Cigarette Liquids by high-Performance Liquid Chromatography-Tandem Mass Spectrometry. aCS omega. 2019;4(13):15364-15372. doi:10.1021/acsomega.9b01255