Journal of Food and Nutrition Research, 2019, Vol. 7, No. 1, 51-64 Available online at http://pubs.sciepub.com/jfnr/7/1/7 Published by Science and Education Publishing DOI:10.12691/jfnr-7-1-7 Polycyclic Aromatic Hydrocarbon Contamination in Three Tea Samples Collected in Two Different Areas of Vietnam Duong Thanh Nguyen, Phuong Duc Luu, Tien Duy Doan, Yen Hai Dao, Giang Truong Le * Institute of Chemistry – Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Hanoi 10000, Vietnam *Corresponding author: hoasinhmoitruong.vast@gmail.com Received October 28, 2018; Revised December 14, 2018; Accepted January 24, 2019 Abstract The present work was undertaken to identify and determine the concentration of PAHs in forty samples of three different types of tea (green, oolong and black teas) collected in two provinces of Vietnam (Thai Nguyen province in the North and Lam Dong province in the South). For sample preparation, the quick and simple QuEChRES procedure was used and eighteen PAHs congeners were detected by gas chromatography–tandem mass spectrometry (GC-MS/MS), with the percentage recovery higher than 70%. The concentration of the total 18 PAHs in tea samples ranged from 154.2 to 709.0 μg/kg with the highest of total PAHs found in black tea samples. Nine PAHs congeners were found in all samples with wide ranges of concentrations as follows: 1-methylnapththalene (3.6 – 73.1 μg/kg), Acenaphthene (1.6 – 45.0 μg/kg), Fluorene (4.2 – 49.5 μg/kg), Anthracene (2.1 – 40.0 μg/kg), Pyrene (19.3 – 224.9 μg/kg), Chrysene (4.6 – 233.0 μg/kg), Benzo (b) fluoranthene (0.6 – 23.7 μg/kg), Indeno (1,2,3,cd) pyrene (1.0 – 38.4 μg/kg), and Dibenzo (a,h) anthraxcene (1.1 – 25.0 μg/kg). 3–4 rings PAHs were dominant in all tea samples, with a contribution of 66.0 – 84.3% of the total 18 PAHs content. The average content of the indicated PAHs in oolong tea from the South (OS) was the lowest and that of black tea from the South (BS) was the highest. It was also observed that the toxic equivalent (TEQ) values of tea samples from the North higher than those from the South. Keywords: tea, food safety, polycyclic aromatic hydrocarbons (PAHs), QuEChERS, gas chromatography–tandem mass spectrometry (GC-MS/MS) Cite This Article: Duong Thanh Nguyen, Phuong Duc Luu, Tien Duy Doan, Yen Hai Dao, and Giang Truong Le, “Polycyclic Aromatic Hydrocarbon Contamination in Three Tea Samples Collected in Two Different Areas of Vietnam.” Journal of Food and Nutrition Research, vol. 7, no. 1 (2019): 51-64. doi: 10.12691/jfnr-7-1-7. 1. Introduction Tea is one of the most consumed beverages with the global tea market was valued at around USD 49,456.52 million in 2017 and is expected to reach approximately USD 73,132.82 million by 2024 [1]. The health effects of tea leaves have been widely studied [2,3,4]. There are a lot of scientific reports indicating that tea consumption might have health promoting properties like cholesterol reduction, antioxidant features, and protection against cardiovascular disease [5,6,7,8,9]. But it has also been suggested that certain pollutants in tea leaves may pose a health threat to tea drinkers [10,11]. Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds consisting of conjugated benzene rings arranged in different configurations. It has been shown that many of PAHs are toxic, and some of them have been proven carcinogenic and genotoxic [12,13,14,15,16]. The US Environmental Protection Agency (EPA) has identified 16 PAHs as priority environmental pollutants to include Acenaphthene (ACP), Acenaphthylene (ACNP), Anthracene (AN), Benzo(a)anthracene (B(a)A), Benzo(a)pyrene (B(a)P), Benzo(b)fluoranthene (B(b)F), Benzo(g,h,i)perylene (B(ghi)P), Benzo(k)fluoranthene (B(k)F), Chrysene (Chy), Dibenz(a,h)anthracene (DBA), Fluoranthene (FLA), Fluorene (FL), Indeno(1,2,3- cd)pyrene (IP), Naphthalene (NaP), Phenanthrene (PHN), Pyrene (Py) [17]. In particular, B(a)P is a well-known substance classified by the International Agency for Research on Cancer (IARC) into group 1 of carcinogens— i.e., factors with proven harmful (carcinogenic) effects on the human body—while B(b)F, Chy and B(a)A are classified into group 2B—i.e., group of compounds with a possible carcinogenic effect on the human body [18,19,20]. These compounds are commonly called PAH4 which can serve as an indicator for the occurrence of PAHs in food [21,22]. Following the scientific opinion of the European Food Safety Authority (EFSA), the European Commission fixed limits for the sum of PAH4 in different foodstuffs in the amendment 835/2011 of the regulation 1881/2006