Assessing the contamination levels of dried teas and their infusions by polycyclic aromatic hydrocarbons (PAHs)

The occurrence of 16 polycyclic aromatic hydrocarbons (PAHs) in 68 brands of teas, bought in Poland, was surveyed using ultrasonic extraction of dried teas and liquid-liquid extraction of infusions. The extracts were cleaned by solid phase extraction. The instrumental analysis was performed using gas chromatography coupled with mass spectrometry (GC-MS). The total content of 16 PAHs ( n-ary sumation 16PAHs) ranged from 41.5 to 2910.2 mu g/kg in dried teas and from 52.9 to 2226.0 ng/L in infusions. Benzo(a)pyrene was found from below limit of quantification to 75.7 mu g/kg in dried teas and from limit of detection to 18.7 ng/L in infusions. The least contaminated samples were herbal and fruit teas, while traditional black, green, red, and white teas, i.e. teas made of Camellia sinensis, were more polluted. Positive correlations between dried traditional teas and their infusions were observed. The mean transfer rates of n-ary sumation 16PAHs from dried materials into water ranged from 2.4 to 25.3%. The total toxicity of the tested teas largely corresponded to the sum of 4 PAHs ( n-ary sumation 4PAHs) chosen by the European Food Safety Authority as indicator of PAHs in food. Estimated PAHs uptake and margin of exposure pointed to low health risks associated with drinking tea infusions.