An analytical method to quantify tetrabromobisphenol A (TBBPA) and its conjugated metabolites in rat serum or other biological samples

Brominated flame retardants (BFRs) are widely used to enhance fire resistance in consumer and commercial products, but often leach into the environment due to their surface application. Tetrabromobisphenol A (TBBPA), the most applied BFR, has been detected in human serum, urine, and breast milk. TBBPA is readily absorbed from the gastrointestinal tract, undergoing first-pass hepatic metabolism to form the two major metabolites TBBPA-sulfate and TBBPA-glucuronide. Despite evidence linking TBBPA exposure to developmental toxicity, neurobehavioral effects, uterine cancers, and endocrine disrupting potential via thyroid hormone interference, exposure assessments remain challenging. Current methods rely heavily on direct quantification of TBBPA and its metabolites using liquid chromatography-mass spectrometry (LC-MS), but a lack of commercially available TBBPA metabolites at analytical standards is a limiting factor. This study introduces a method to rapidly quantify TBBPA, and after enzymatic deconjugation, its metabolites using LC-Orbitrap. Using this method, TBBPA-glucuronide was the only metabolite detected in rat serum following oral exposure. Native TBBPA was obtained using enzymatic deconjugation of serum. The protocol simplifies exposure evaluation by offering a practical, and rapid, approach for quantifying TBBPA in biological samples.