One-step electrodeposition of poly(o-phenylenediamine)-Zn composite on plaswood propeller as an extraction device for polycyclic aromatic hydrocarbons in coffee.

Coffee beans can be contaminated during roasting by polycyclic aromatic hydrocarbons (PAHs), some of which have been classified as carcinogens. An extraction device for PAHs in coffee drinks was designed with six compact DC motors rotating six sorbents. The sorbents were plaswood propellers modified by one-step electrodeposition of a poly(ortho-phenylenediamine) and Zn composite (PoPD-Zn). Benzo(a)anthracene (BaA), chrysene (Chry), benzo(b)fluoranthene (BbF), and benzo(a)pyrene (BaP) were chosen as representative PAHs. Scanning electron micrographs of the PoPD-Zn showed a porous structure. The extracted PAHs were quantified by gas chromatography coupled with a flame ionization detector. Detected concentrations of PAHs in coffee drink samples were as follows: BaA 1.4 ± 0.4 to 16.5 ± 0.8 µg L; Chry 0.5 ± 0.2 to 2.1 ± 0.5 µg L; BbF 2.2 ± 0.6 µg L; and BaP 6.2 ± 1.0 µg L. Good recoveries ranging from 82.7 ± 1.9% to 99.0 ± 0.5% were obtained.