Analysis of main metallic components and material types of metallic materials in contact with e-liquids found in commercial electronic cigarettes

In order to determine the main metallic components and material types of metallic materials in contact with e-liquids found in commercial electronic cigarettes, 44 types of metallic materials from 15 e-cigarettes, including 15 filaments, 8 welding joints, 3 wires and 18 other metallic materials within e-liquid storage cavity, were collected. These materials were digested by nitric acid and hydrochloric acid with microwave before qualitative analysis under full scan model and semi-quantitative analysis by inductively coupled plasma mass spectrometry(ICP-MS). The results showed that:1)Limit of detection of the method was lower than 0.2 μg/L, and relative standard deviation was lower than 6.0%. 2)All the filaments of e-cigarettes were mainly made of nickel and chromium; filaments and thick wires were joined to each other by mainly copper and zinc soldering; the thick wires were mainly made of nickel alloys. Cu-Zn alloys and Sn-Cr alloys were widely used in components in contact with e-liquids(liquid storage cavity)of e-cigarettes. This method is sensitive with good repeatability and suitable for the rapid determination of metal elements from metallic materials found in electronic cigarettes.