High-Sensitivity Method for Determination of Tetrabromobisphenol-S and Tetrabromobisphenol-A Derivative Flame Retardants in Great Lakes Herring Gull Eggs by Liquid Chromatography−Atmospheric Pressure Photoionization−Tandem Mass Spectrometry

Tetrabromobisphenol-A-bis(2,3-dibromopylether) (TBBP-A-dbpe), tetrabromobisphenol-A-bis(allyl ether) (TBBP-A-ae), and tetrabromobisphenol-S-bis(2,3-dibromopropyl ether) (TBBP-S-dbpe) are derivatives of tetrabromobisphenol-A (TBBP-A), and are all used as brominated flame retardants (BFRs). Using high-performance liquid chromatography−quadrupole-time-of-flight-mass spectrometry with atmospheric pressure photoionization (APPI) in the negative mode (LC-APPI(−)-Q-TOF-MS) and the novel use of pure acetone as dopant and LC mobile phase, full scan mass spectra showed that for these BFRs the dominant isotopic ion cluster was [M + O2]−, and with other lesser abundant [M + O2 − HBr]−, and [M − H]− fragment ions. Subsequently, highly sensitive quantification of TBBP-A-dbpe, TBBP-A-ae, and TBBP-S-dbpe was accomplished via LC-triple quadrupole mass spectrometry with APPI(−) (LC-APPI(−)-MS/MS) via multiple ion monitoring based on the [M + O2]− > [Br]− transition. Low to sub ng/g (wet weight (w.w.)) method limits of detection (LODs) were achieved, i.e., 0.07, 0.03, and 1.28 ng/g w.w. for TBBP-A-dbpe, TBBP-A-ae, and TBBP-S-dbpe, respectively. A variety of herring gull eggs were screened for these BFRs. The eggs were collected during 2008−2009 from several colony sites in the eastern Laurentian Great Lakes (Ontario) and in the St. Lawrence River (Québec). All egg samples had TBBP-S-dbpe concentrations below the LOD, and TBBP-A-ae and TBBP-A-dbpe were quantifiable in 67%−83% of the samples at concentrations up to 0.56 ng/g wet weight. Thus, TBBP-A-ae and TBBP-A-dbpe are present in herring gull eggs from these populations, bioaccumulate in the herring gull food chain, and are transferred from gull to egg.