Determination of Arsenic Species in Electronic Cigarette Liquid

• Author / Creator

  Schofield, Jordan

• The presence of arsenic in e-liquids of electronic cigarettes has rarely been studied and the few studies that have investigated the presence of arsenic have found either very low, or undetectable concentrations. Additionally, the individual species of arsenic have not been thoroughly explored due to the viscosity of the sample matrix. The focus of this research was to determine both the total arsenic concentration and concentrations of individual arsenic species present in e-liquids. A total of 96 e-liquid samples were purchased from three online vendors and selected based on popularity. For the determination of total arsenic concentrations, inductively coupled plasma mass spectrometry (ICP-MS) was used. Arsenic was detected in 81 of 96 e-liquid samples with most (62/81) having concentrations under 3 µg/kg. Only eight e-liquids had elevated arsenic concentrations greater than 5 µg/kg, with five having concentrations between 16 and 36 µg/kg. Due to the multi-element capability of ICP-MS, fourteen other elements including antimony, cadmium, chromium, cobalt, and lead were also determined. Arsenic species were investigated using ion pair and anion exchange high performance liquid chromatography (HPLC) separation with ICP-MS detection, however arsenic species concentrations were only determined using anion exchange HPLC-ICP-MS. Four arsenic species; arsenite (AsIII), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and arsenate (AsV) were determined in the eight e-liquids with arsenic concentrations higher than 5 µg/kg. Both AsV and AsIII were present in all eight samples, with AsV having the highest concentration in seven of the eight samples with a median concentration of 4.42 µg/kg, followed by AsIII which had a median concentration of 1.72 µg/kg. Inorganic arsenic (AsIII + AsV) concentrations in the eight e-liquids were between 3.6 µg/kg to 16.3 µg/kg and from these e-liquids inorganic arsenic concentrations in the air were estimated to be between 2.7 µg/m3 to 12.2 µg/m3. When compared to the PEL set by OSHA of 10 µg/m3, the upper range of 12.2 µg/m3 is greater, meaning that if an e-cigarette user were to vape for an eight-hour period they could be exposing themselves to inorganic arsenic concentrations in the air greater than the recommended PEL set by OSHA. Four unknown arsenic species were also detected in 50% - 88% of the samples analyzed highlighting the need for additional research to determine the identity of these unknown arsenic species.

• Subjects / Keywords

  • E-liquids
  • Arsenic
  • Arsenic species
  • E-cigarettes
  • Electronic cigarettes

• Graduation date

  Fall 2022

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-w5cg-0v91

• License

  This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.