Determination of Polycyclic Aromatic Hydrocarbons in Water- and Gin-Based Tea Infusions of Selected Tea Brands in Nigeria

Abstract

The concentrations of the 16 priority polycyclic aromatic hydrocarbons (PAHs) in tea infusions made of water and local gin (alcohol) were investigated with a view to providing information on the profiles and health hazards associated with these two common Nigerian methods for tea consumption. The water-based tea infusion was prepared by submerging 4 g of tea in boiling water and allowing it to stand for 15 min, while the gin-based infusion was simply prepared by submerging 4 g of tea in gin at room temperature and allowing it to stand for 15 min. The concentrations of the ∑16 PAHs in the infusions were measured by using gas chromatography equipped with a flame ionization detector (GC-FID) after ultrasound-assisted extraction and clean-up. The concentrations of the ∑16 PAHs ranged from 24.9–623.4 μg kg⁻¹ with a mean value of 177 μg kg⁻¹ and 36.8–438.3 μg kg⁻¹ with a mean of 189 μg kg⁻¹ for water- and local gin-based infusions, respectively. The concentration of the ∑16 PAHs in the water- and local gin-based infusions of these teas were high when compared with levels reported in the literature for tea infusions. The local gin-based infusions had a higher mean level of the ∑16 PAHs than the water-based infusions. Four- and five-ring PAH compounds were dominant in these tea infusions.

Key Words:

• alcoholic infusion
• health hazards
• PAHs
• tea
• water infusion

ACKNOWLEDGMENTS

The authors are grateful to Mr. Ijeoma Ojelum for his assistance during sample collection and analysis. CMAI is grateful to the University of KwaZulu-Natal, South Africa for the award of a Post-doctoral Fellowship.