The direct analysis of trace levels of glycidol from e-liquids and e-cigarette emissions by GC-MS, is confounded by its size and the limited number of specific ions available for quantification. It is also susceptible to artificial formation resulting from either degradation or reactivity of the propylene glycol (PG) and vegetable glycerin (VG) matrix in the GC injection port. Therefore, a method was developed using derivitization to increase the selectivity and sensitivity for the quantification of glycidol in e-cigarette matrices.

Gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode, with deuterated glycidol-d5 as internal standard, was used to quantify trace amounts of glycidol in e-liquids and emissions from e-cigarettes. Solid phase extraction (SPE) was applied to reduce the impact of the PG and VG matrix on the derivization procedures. Two selective derivatizations were conducted to form the 3-bromo-1,2-propanediol-phenylboronic acid derivative of glycidol.

The calibration range was from 1 ng/mL to 500 ng/mL, with a test sample limit of quantitation (LOQ) equivalent to 66.7 ng/g for e-liquids and 20.2 ng/collection for e-aerosol. The accuracy and precision were determined using lab fortified blank (LFB) samples and lab fortified matrix (LFM) samples. LFB recoveries of glycidol spiked at 100 ng/mL, ranged from 98.4 % to 109 %. The fortified matrix recoveries ranged from 94.8 % to 120 % for samples spiked with 5 ng/mL glycidol, 95 % to 105 % for samples spiked with 100 ng/mL, and 101 % to 106 % for samples spiked with 450 ng/mL of glycidol. Stability and robustness was confirmed with acceptable recoveries of samples with slight modification on several critical parameters during sample preparation.

In conclusion, this novel approach was able to accurately determine trace amounts of glycidol in both e-liquids and e-aerosol.