Method development and validation for the determination of polybrominated diphenyl ether congeners in Brazilian aquatic sediments

An analytical method was developed and validated for the determination of nine PBDE congeners (BDE 28, 47, 66, 85, 99, 100, 138, 153 and 154) in aquatic sediment samples using ultrasonic solid-liquid extraction (acetone:n-pentane 1:1 v/v) followed by gas chromatography coupled with electron capture detection. Values for LOD varied between 0.58 and 0.96 ng g− 1 while LOQ ranged from 1.92 to 3.21 ng g− 1. Fortified and certified reference sediments were investigated for method accuracy and precision. Recovery, varying from 87.7 ± 6.6% (BDE-138) to 98.7 ± 1.4% (BDE-28), was influenced by strong hydrophobic interactions between analytes and the sediment matrix. The validated method was successfully used to assess PBDE levels in a Brazilian sediment sample collected at the Paranoá Lake, in Brasília (Brazil). Results revealed environmental concentrations above the reported LOQ for two of the nine PBDE congeners being the BDE-66 the most prevalent (8.1 ± 0.4 ng g− 1) followed by BDE-47 (2.51 ± 0.02 ng g− 1). Further investigations are still needed to evaluate the contamination pattern of PBDE in Brazilian sediments, notably in urbanized regions.