Determination of 2-Chloro-1,3-propanediol (2-mcpd) and 3-Chloro-1,2-propanediol (3-MCPD) in emissions by gas chromatography-mass spectrometry (GC-MS)
Monochloropropanediol (MCPD) and glycidol are thermally generated toxicants found in refined vegetable oils and glycerin. The purpose of this study was to develop a method for the quantitation of 2-Chloro-1, 3-propanediol (2-MCPD) and 3-Chloro-1,2-propanediol (3-MCPD) in the emissions from various nicotine and glycerin containing products.
Total particulate matter (TPM), or the aerosol collected mass (ACM) equivalent, is collected on a glass fibre filter pad. Internal Standard (ISTD) solution containing 2-MCPD-d5 and 3-MCPD-d5 is added to the pad and extracted with isopropyl alcohol (IPA). An aliquot of the extract is combined with a phenylboronic acid (PBA) solution in diethyl ether to form the PBA derivatives (MCPD-PBA). The sample is concentrated to dryness and reconstituted in isooctane. The samples analyzed by GC-MS using a DB-5 UI 60m x 0.25mm x 0.25µm fused silica capillary column and selected ion monitoring (SIM) data acquisition mode. Quantitation is achieved through internal standard calibration.
A common set of calibration standards ranging from 40 to 10000 ng/mL is used for the combustibles and heated tobacco products emission matrices. E-vapour products are analyzed using a calibration range from 12 to 40 ng/mL. Trapping efficiency studies performed by adding impingers containing IPA showed no detectable levels of either 2-MCPD or 3-MCPD in the vapour phase. Recoveries of 2-MCPd and 3-MCPD using fortified samples of the KR 1R6F ranged from 87 to 116% and 97.5 to 114% respectively, showing excellent accuracy across a range of fortified levels.