Substituted polycyclic aromatic hydrocarbons (SPAHs) are found everywhere in the environment due to their persistent and widespread sources. They are formed from their corresponding polycyclic aromatic polycarbons (PAHs). Biphenyl (BP) is found naturally in coal tar, crude oil (up to 0.4 mg/g) and natural gas (3-42 g/m3) and is also used as a wood protecting agent (1). Anthraquinone (AQ) or 9.10 anthracendion is an oxidation product of anthracene, a light, polycyclic aromatic polycarbon (PAH). So AQ is an OXY-PAH, but because it is possible to use it as a pesticide (a so-called bird repellent), its residues, like biphenyl, are controlled by Regulation (EG) 396/2005 (2), which means it is treated like a pesticide.
Altogether we analysed 20 different coconut products taken directly from the market and raw materials from different countries for diverse SPAHs. Most of the products were free of critical findings. But three products showed significant amounts of AQ and BP. In order to find the source of both of these chemicals, we examined the drying procedure used for the coconut meat processing. We burned the coconut shells and analysed their smoke for AQ and BP.
By analysing the coconut shell smoke, we could prove that AQ and BP as well as other SPAHs could develop in the drying process.
Publications on this Subject:
D. Dohmberg, A. Romanotto, J. Scholl, M. Vogt, Sources for Anthraquinone and Biphenyl in Coconut Oils, RAFA 2017 06/11-10/11, Prague