Polycyclic aromatic hydrocarbons (PAHs) in yogurt samples

The concentrations and distributions of major polycyclic aromatic hydrocarbons (PAHs) were determined in 20 kinds of yogurt specimens collected from Italian supermarkets using reversed phase high-performance liquid chromatography equipped with a fluorescence detection. The method was validated by determination of recovery percentages, precision (repeatability), and sensitivity (detection limits) with yogurt samples fortified at 0.25, 0.5 and 1 ng/g concentration levels. The recovery of 14 PAHs, with the exception of naphtalene and acenaphtene, ranged from 61 to 130% and from 60 to 97% at all the levels for yogurts with low (0.1%) and high (3.9%) fats, respectively. The method is repeatable with relative standard deviation values <20% for all analytes. The results obtained demonstrate that acenaphtene, fluorantene, phenanthrene, anthracene, fluoranthene and pyrene were found in all the samples with a similar distribution but different contents when yogurts with low and high fats were compared.