Contamination of Tea and Tea Infusion with Polycyclic Aromatic Hydrocarbons.

Alicja Zachara,Lesław Juszczak,Dorota Gałkowska

doi:10.3390/ijerph15010045

Abstract

The aim of this work was to validate the method of determination of polycyclic aromatic hydrocarbons (PAHs), i.e., benzo(a)pyrene and sum of benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene and chrysene in different types of tea, as well as to assess the transfer of these contaminants from tea to tea infusion. The research materials were popular types of black, green, red and white tea. Quantitative and qualitative determination of PAHs was performed by High Performance Liquid Chromatography with fluorimetric detection (HPLC-FLD). The samples were prepared by QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) technique followed by cleaning-up by dispersion solid-phase extraction (d-SPE). Values of limit of detection and limit of quantification obtained in the validation of the method were lower than the respective maximum values given in Commission Regulation (EU) No. 836/2011. The level of contamination of popular teas commercially available on the Polish market with PAHs is similar to that of teas available in other countries, with a very large variation in the concentration of each of the compounds. The highest benzo(a)pyrene and Σ4PAHs contents (209 ± 42 μg/kg and 756 ± 151 μg/kg, respectively) were found for black tea leaves. The transfer of Σ4PAHs from black tea to tea infusions was 0.48%, while it was 1.55–1.72% for red, white and green teas.

Highlights

The tea leaf infusion (Camellia sinensis) is one of the most widely consumed beverages in the world due to its palatability, the tradition of preparing and drinking, and the wide variety of commercially available tea species
The aim of this work was to validate the method of determination of polycyclic aromatic hydrocarbons (PAHs), i.e., benzo(a)pyrene (BaP), benz(a)anthracene (BaA), benzo(b)fluoranthene (BbFA) and chrysene (Chr) (individually and as a sum of the four PAHs (Σ4PAHs)), as well as to assess the transfer of these contaminants from tea to tea infusion
In order to assess the repeatability of the method, twenty analyses of BaP, BaA, BbFA and Chr contents in black tea were performed

Summary

Introduction

The tea leaf infusion (Camellia sinensis) is one of the most widely consumed beverages in the world due to its palatability, the tradition of preparing and drinking, and the wide variety of commercially available tea species. The chemical composition of the finished tea product depends on both chemical composition of the raw material (plant) and on the tea processing. The former is determined by environmental factors including cultivation method, atmospheric conditions and the harvesting period [2]. Environmental pollution can contribute to contamination of tea with heavy metals, dioxins, pesticide residues and polycyclic aromatic hydrocarbons (PAHs) [3,4] The latter can be adsorbed with dust particles on tea leaves and buds or can be respired by plant from air [5,6]

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Conclusion