Levels of Polyaromatic Hydrocarbons in Egyptian Vegetables and Their Behavior During Soaking in Oxidizing Agent Solutions

The residues of persistence potentially toxic organic compounds polyaromatic hydrocarbons (PAHs) were measured in 13 species of edible vegetables collected from Great Cairo governorate (Egypt). And the efficient role of washing by oxidizing agents hydrogen peroxide (H2O2), potassium permanganates (KMnO4) and midribs of cabbage leaves solutions on the elimination of PAHs from contaminated vegetables was investigated. Vegetable samples were all soxhlet-extracted in triplicate, cleaned up by open chromatography and analysed using gas chromatography with mass selective detection. It was observed that all tested vegetables have been contaminated with PAHs. The total content of 16 PAHs ranged from 1.22 to 12.63 ppb with the highest PAHs found in leafy vegetables. PAHs (3-4 rings) were dominant in all vegetable samples. The results also indicates the efficient role of washing by oxidizing agent in elimination of PAHs from naturally contaminated carrots. Midribs of cabbage leaves solution is the most efficient in removing PAHs followed by H2O2 and KMnO4. the removal percentages of the total PAHs ranged from 65.5 to 97.8% and from 79.4 to 99.9% at 4 and 8% concentrations of oxidizing reagents, respectively.