Development of vibrational spectroscopic methods combined with chemometrics for the detection and quantification of nicotine in e-liquids.

E-cigarette have become a popular alternative to smoking tobacco cigarettes. They are sold in vapeshops and online. However, in Belgium, it is prohibited to import or to buy nicotine-containing e-liquids via the internet. The ban on long-distance sale implies that postal packages containing e-liquids are checked at customs. Furthermore, there is a demand of vapeshop-inspectors for on-site screening of e-liquid samples to check their compliance to the TPD i.e. non-nicotine labeled e-liquids should not contain nicotine and the maximum nicotine concentration of nicotine-labeled e-liquids should be respected (< 20mg/ml). The main objective of this paper is to develop a handheld NIR, Raman or SERS spectroscopic method combined with chemometrics (PLS and PCA) for detection and quantification of nicotine in e-liquids out of the laboratory. Raman and SERS, combined with chemometrics were proved to be promising tools for the detection and quantification of nicotine in e-liquids. However, improvement of Raman PLS model and further SERS studies with tests on a larger number of samples are still needed.