2,2−Bis[3,5−dibromo−4−(2,3−dibromo−2−methylpropoxy)phenyl]propane (CAS No.: 97,416−84−7, BDDMP), also known as Tetrabromobisphenol A−bis(2,3−dibromo−2− methylpropyl ether) (TBBPA−BDBMPE), is a novel brominated flame retardant (BFR) primarily used in expanded and extruded polystyrene foam (EPS and XPS) for building insulation. It was proposed as an alternative to hexabromocyclododecane (HBCD) by the United States Environment Protection Agency (EPA) in 2014[1], after HBCD was listed in the Annex A of the Stockholm Convention on Persistent Organic Pollutants (POPs) due to its high toxicity, bioaccumulation and persistence. Since the usage of HBCD as a flame retardant was officially banned in EPS and XPS, BDDMP was produced and used in the building industry at a scale of thousands of tons in China. 400 to 500 thousand tons of EPS and XPS containing BDDMP were exported to Europe, America, Southeast Asia and other countries all across the world each year and the amount is still growing. However, the environmental fate and risks[2] of BDDMP have not received attention commensurate with its rapidly expanding production volume.

During the transition from legacy brominated flame retardants (BFRs) to novel alternatives it is essential to simultaneous determination of both classes, in order to verify the phase−out success and assess the environmental behavior of substitutes. This is particularly urgent in BFR manufacturing clusters where historical residues and current emissions co−exist. BDDMP−producing facilities are usually located in bromine−rich regions where several BFRs are manufactured concurrently. Tetrabromobisphenol−A bis(2,3−dibromo−2−propyl ether) (TBBPA−BDBPE, BDDP) differs from BDDMP by only two methyl groups, is synthesized through an analogous route, and is co−produced as a major BFR. BDDP has been reported to having hepatotoxicity similar to Tetrabromobisphenol−A (TBBPA)[3] and to exhibit potential neuro−toxicity[4] and reproductive toxicity[2,5]. TBBPA, the common intermediate of BDDMP and BDDP and once the most widely used BFR[6], is still detectable in products and surrounding environments. Decabromodiphenyl ether (DBDPO, BDE−209) and HBCD were completely banned in China and most countries in the world because of their POPs characteristics and toxicity[7], yet residual contamination persists near historical production sites. Therefore, having a thorough assessment of the societal[8] and environmental impacts[9] of BDDMP manufacturing and application demands an analytical method capable of high sensitivity, robustness, and specificity when applied to diverse matrices.

The detection of HBCD, DBDPO and TBBPA mostly uses GC−MS methods[[10], [11], [12], [13], [14]]. However, interpretation of GC−MS mass spectra of BDDP has been considered "far−fetched" [15]. The high molecular weight and thermal lability of BDDMP make GC−based approaches problematic. LC−MS/MS methods are therefore preferred for TBBPA and its derivatives. Both electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) have been employed for the detection of TBBPA and derivatives, but the low polarity of TBBPA derivatives hinders the formation of molecular ion using ESI[16]. Yang et al. [15] split TBBPA/S and their derivatives into two polarity groups, analyzing TBBPA by ESI and BDDP by APCI, obtaining instrument detection limits (IDLs) of 0.26 pg and 2.45 pg (5 µL injection), respectively. Liu et al. [17] used HPLC−ICP−MS/MS and reported IDLs of 6 pg (50 µL injection) for both TBBPA and BDDP. HPLC methods have also been reported for DBDPO in water (MLD=0.7 ng/mL)[18] and sediment (LOQ=1.2 ng/g)[19] using variable−wavelength detector and APPI−MS/MS as detector, respectively. HPLC−ESI−MS/MS provides excellent performance for the detection of HBCD in various matrices[[20], [21], [22]] (IDLs ranging from 4.3 pg to 4.5 pg, 10 µL injection).

For the simultaneous determination of emerging and legacy BFRs, a single−injection LC−MS/MS method was developed for BDDMP, BDDP, TBBPA, DBDPO and HBCD. This method was successfully applied to EPS/XPS, airborne PM10, soils, surface water and sediments collected from a major BFR manufacturing cluster (annual BDDMP production capacity> 10,000 t). This study represents the first comprehensive assessment of this emerging contaminant from a primary source, establishing a vital method for investigating its multi−media environmental behavior and life−cycle management.