determination of benzo[a]pyrene in traditional, industrial and semiindustrial breads using a modified quechers extraction, dispersive spe and gc-ms and estimation of its dietary intake.

a fast and simple modified quechers extraction method was developed for determination of benzo[a]pyrene (bap) in 137 traditional (sangak), semi-industrial (sangak) and industrial bread samples using spiked calibration curves by gc/ms. sample preparation includes extraction of bap into acetone followed by cleanup with dispersive solid phase extraction. the limit of detection and limit of quantification were 0.3 ng/g and 0.5 ng/g, respectively. the values for recoveries and rsd were calculated as 110.5-119.85% and <11.6% respectively. average concentration of bap in sangak bread samples of shiraz and tehran was 0.59 and 0.60 ng/g, respectively. 35.5% of samples of breads collected in tehran were contaminated with bap at the amount higher than maximum levels regulated in processed cereal-based foods and baby foods by european commission (1 ng/g). seventeen percent of samples of breads collected in shiraz were contaminated with bap which 13% of total samples were >1 ng/g. bap content in all industrial samples was lower than loq. assuming the consumption of bread in tehran and shiraz is limited to these kinds of breads, the daily intake of bap in tehran and shiraz population through bread consumption was estimated to be 170.6 and 168.7 ng/day, respectively. this is the first report concerning contamination of bread samples with bap in iran.