Determination of benzo(a)pyrene by GC/MS/MS in retail olive oil samples available in Qatar.

A survey was carried out for the presence of benzo(a)pyrene (B(a)P) in olive oils following reports that some batches of Spanish olive-pomace oil and its products contained high levels of B(a)P. Three types of olive oils (1) virgin olive oil, (2) refined olive oil and (3) olive-pomace oil, originating from France, Greece, Italy, the Lebanon, Spain, Tunisia and Turkey, and available on Qatar market, were analysed for B(a)P. Determination was carried out by extraction from a cyclohexane solution with N,N-dimethylformamide: water (9:1), back extraction with cyclohexane, followed by clean-up on a silica gel column and quantification by GC/MS/MS. The recovery and limit of quantitation of B(a)P in olive oils by this method were estimated as 88% and 0.5 microg kg(-1), respectively. B(a)P was detected in amounts below the permitted level of 2 microg kg(-1) in all 31 virgin olive oil samples and in 13 refined olive oil samples. However, all seven samples of Spanish olive-pomace oil produced and packed in Spain and three samples of olive-pomace oil produced in Spain, but packed in Saudi Arabia, were found to be contaminated with B(a)P, the level ranging from 3.1 to 70.8 microg kg(-1). In two samples of olive-pomace oil originating from Greece, B(a)P was not detected.