Effect of Biogenic Impurities on Polycyclic Aromatic Compounds Analysis by Fluorimetry

Abstract

Polycyclic aromatic compounds (PAC) are ubiquitous in nature. The International Oceanographic Commission (IOC) has recommended their analysis in environmental samples, by ultra-violet/fluorescence (uv/f) spectrophotometry. In the present investigation, the effect caused by the presence of biogenic impurities on the perceived PAC concentration of anthropogenic solutions was examined. Lipid extracts of the foot of the clam, Mya arenaria, the muscle tissue of cod, Gadus morhua and of the harbour porpoise, Phoceana phoceana, as well as squalene represented the biogenic material. Venezuelan crude, no.2 fuel oil and chrysene were chosen as the PAC solutions, representing environmental extracts. Results indicate that more than 30–100 ng/μl or 0.045–0.150 mg/g (dry weight) of lipid extracts are needed to start to affect (>5–10%) the perceived PAC concentrations, while the amount of squalene needed is over 370 ng/μgl or 0.555 mg/g (dry weight). The latter is above levels reported in tissues of most marine animals, except sharks. This supports the value of fluorimetry as a relatively inexpensive screening technique for monitoring PAC levels in marine organisms. However, it does not diminish the importance of analysing samples by gas chromatography-mass spectrometry to obtain more detailed information.

Key Words:

• Fluorimetry
• PAH
• hydrocarbons
• squalene
• muscle
• lipids.