Counterfeit and illicit tobacco may contain potentially toxic organic impurities that result in adverse health effects to
the consumer. The aim of this work was to investigate the feasibility of the identification of organic impurities in counterfeit
or illicit tobacco using attenuated total reflectance-Fourier transform infrared (ATR-FT-IR) spectroscopy.
Counterfeit tobacco is a public health threat that can have hazardous consequences on the consumer. In the UK, counterfeit
cigarettes have a high prevalence of 15% and cost the taxpayers about £2 billion per year (1,2). Smoking in general remains
one of the leading causes of preventable deaths. Tobacco smoking results in toxic consequences because of the presence of
carcinogenic compounds such as nitrosamines and polycyclic aromatic hypdrocarbons (3,4). Moreover, it is expected that morbidity
and mortality because of smoking tobacco will rise to 8 million per year in 2030 (5).
It is noteworthy to distinguish between counterfeit and illicit tobacco products. Illicit tobacco products represent tobacco
products that are imported from non-European Union (EU) sources. These products may be authentic, but are smuggled into the
country, and thus affect the legitimate trade and revenue of tobacco significantly. On the other hand, counterfeit tobacco
products are not regulated and may contain all sorts of hazardous ingredients. In most cases, the manufacturing source of
counterfeit tobacco is unknown. However, it was reported that the main sources of counterfeit tobacco in the UK were manufactured
in the Far East (5). Counterfeit tobacco could contain potentially toxic impurities of elemental and organic nature. Elemental
impurities reported in counterfeit tobacco include cadmium, lead, and thalium (6–8). Both cadmium and lead were reported as
carcinogenic (9). Moreover, cadmium has shown to affect the cardiovascular and respiratory systems (3). On the other hand,
organic impurities reported in counterfeit tobacco comprised the following compounds (10,11): ammonium salts, caffeine, chlorogenic
acid, formic acid, glucose, isopropanol, methanol, propylene glycol, quinic acid, and sucrose. Also, counterfeit tobacco products
were found to contain higher amounts of nicotine than authentic alternatives (10).
Subsequently, it is important to identify the organic and elemental toxic constituents in counterfeit tobacco. The literature
focuses mainly on identifying elemental constituents in counterfeit tobacco, and few studies investigate the organic components.
In this respect, elemental techniques used for the identification of counterfeit tobacco include inductively coupled plasma–optical
emission spectrometry (ICP-OES) (6,12,13), and energy dispersive polarized X-ray fluorescence (EDPXRF) spectroscopy (8).
Most of the organic techniques used for the identification of counterfeit tobacco were destructive and included gas chromatography–flame
ionization detection (GC–FID) for the determination of nicotine (6), light-emitting diode (LED)-induced fluorescence spectroscopy
(14), liquid chromatography (LC) (15), and nuclear magnetic resonance (NMR) (10,16). However, these methods require time,
money, and extensive sample preparation. Subsequently, nondestructive identification of counterfeit cigarettes was also done
using near-infrared spectroscopy (NIR) (17–19). NIR spectroscopy is rapid and easy to apply, however it requires enough sample
from each tobacco product. On the other hand, attenuated total reflectance-Fourier transform infrared (ATR-FT-IR) spectroscopy
offers the advantage of measuring a small amount of sample (such as a few milligrams) in minimum time. Therefore, the aim
of this work was to investigate the potential of ATR-FT-IR spectroscopy for the identification of potential toxic impurities
in illicit and counterfeit tobacco products.