Evaluation of polycyclic aromatic hydrocarbons and some heavy metals in roasted food snacks in Amassoma, Niger Delta, Nigeria

Abstract

Analysis of raw and roasted ready-to-eat foods namely; Atlantic mackerel (Scomber scombrus), suya beef and plantain (Musa paradiasca) sold and consumed in Amassoma town were screened for the presence of 15 polycyclic aromatic hydrocarbons (PAHs). Concentration of chromium, lead and cadmium were also determined after digestion with aqua regia and analysed using atomic absorption spectrophotometer. Column chromatography, packed with anhydrous Na₂SO₄ and silica gel was used for PAH extraction with dichloromethane as the eluting solvent. The identification and concentration of PAHs were carried out by gas chromatography GC/FID with the aid of 15 PAH standards. Appreciable amount of benzo[a]pyrene (2.41 μg/g) and benzo[b]fluoranthene (4.51 μg/g) were found present in roasted mackerel fish; while a mean of 7.23 μg/g of benzo[a]anthracene was detected in suya beef. Thirteen (13) other PAHs were present at various concentrations in the smoked fish. No PAH was detected in roasted plantain and in the raw food items. Levels of the heavy metals were found in trace amounts and were below World Health Organization limits for human consumption.

Key words: Gas chromatography, benzo[a]pyrene, chromium, lead, smoked fish, suya plantain.