The presence of trace metals in e-liquids or aerosol of electronic cigarettes (e-cigarette) has been previously reported^[1]. It has also been demonstrated that contamination with tin, aluminum, copper, iron and nickel may occur from certain parts of a standard smoking machine^[2]. Therefore, the risk of a possible transfer of trace metal from e-liquids or components of e-cigarette devices into aerosol needs to be carefully investigated.

In this study, both rotary and linear smoking machines fitted with impingers and electrostatic precipitation trapping systems were used for sample collection. For the quantification of trace metal concentration levels in aerosols, the fully validated method as presented during the CORESTA Smoke/Techno Joint Study Groups Meeting 2015 was applied. The measurements encompassed seven metals including aluminium, nickel, iron, chromium, copper, tin and silver and were performed with an Inductively Coupled Plasma - Optical Emission Spectrometer (ICP-OES).

The aerosols were generated from clearomiser samples by applying vaping conditions according to the CORESTA Recommended Method (CRM) No. 81.

The quantification was carried out using Yttrium as an internal standard. For the e-aerosol emissions, the limits of quantification (LOQ) ranged from 0.003 µg/10 puffs (copper, iron) to 0.04 µg/10 puffs (tin).

In this study, metal contaminations could be detected in aerosol and blank samples on a similar level when the investigated smoking machines were used. The results obtained by the rotary and linear type devices and the different trapping systems will be compared and discussed along with suggestions to reduce possible contamination sources.

[1] M. Williams, A. Villarreal, K. Bozhilov, S. Lin, P. Talbot; PLOS ONE; Volume 8; Issue 3, 2013
[2] Otte S., Nowak S., Intorp M.; Method Development and Validation: Quantification of Metals in Liquids and Aerosol of e-cigarettes; CORESTA Congress Presentation ST 10; 2015