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

Artur Ciemniak,Kamila Kuźmicz,Maria Fernanda Cadena,Monika Rajkowska-Myśliwiec

doi:10.1007/s00003-019-01229-1

Abstract

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 (∑16PAHs) ranged from 41.5 to 2910.2 μg/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 μg/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 ∑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 (∑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.

Highlights

Polycyclic aromatic hydrocarbons (PAHs) are the group of organic compounds consisting of fused aromatic rings bound in various geometric configurations
16 polycyclic aromatic hydrocarbons (PAHs) recommended by US EPA (1984) were determined (Fig. 1 and Table 2)
On average 16.93% of total PAHs was released into the infusion

Summary

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are the group of organic compounds consisting of fused aromatic rings bound in various geometric configurations. Widespread in the environment, PAHs are by-products of reactions occurring in incomplete combustion of organic matter (pyrolysis). They are formed in homes and industry, when high temperatures are involved. The content of PAHs in Before deposition, gaseous and particle-bound PAHs may be transported over long distances (Simonich and Hites 1995), leading to the contamination of plants, including edible ones. The wax cuticle covering plant surfaces facilitates the adsorption of lipophylic air pollutants. Because they have high surface areas, herb and tea leaves are contaminated with PAHs and other hazardous compounds

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