Hydroxylated 2-Ethylhexyl tetrabromobenzoate isomers in house dust and their agonistic potencies with several nuclear receptors

In the current study, by combining ultra-high resolution (UHR) MS1 spectra, MS2 spectra, and derivatization, three hydroxylated isomers of 2-ethylhexyl tetrabromobenzoate (OH-TBB) were identified in Firemaster (R) 550 and BZ-54 technical products. Also, a new LC-UHRMS method, using atmospheric pressure chemical ionization (APCI), was developed for simultaneous analysis of OH-TBB, TBB, hydroxylated bis(2-ethylhexyl)-tetrabromophthalate (OH-TBPH) and TBPH in 23 samples of dust collected from houses in Saskatoon, SIC, Canada. OH-TBBs were detected in 91% of samples, with a geometric mean concentration of 0.21 ng/g, which was slightly less than those of OH-TBPH (0.35 ng/g). TBB was detected in 100% of samples of dust with a geometric mean concentration of 992 ng/g. Significant (p < 0.001) log linear relationships between concentrations of OH-TBBs, TBB, or OH-TBPHs and TBPH in dust support the hypothesis of a common source of these compounds. OH-TBBs were found to be strong agonists of peroxisome proliferator-activated receptor gamma (PPAR gamma) and weaker agonists of the estrogen receptor (ER), but no agonistic potencies was observed with the androgen receptor (AR). Occurrence of OH-TBBs in technical products and house dust, together with their relatively strong PPAR gamma potencies, indicated their potential risk to health of humans. (C) 2017 Elsevier Ltd. All rights reserved.