Determination of non-halogenated, chlorinated and brominated organophosphate flame retardants in herring gull eggs based on liquid chromatography–tandem quadrupole mass spectrometry

Numerous triester organophosphate flame retardants (OPFRs) have been used for several decades and continue to be used in a variety of commercial products. We developed a sensitive quantitative method for the analysis of, seven non-halogenated, three chlorinated and two brominated OPFRs of known or possible environmental relevance in herring gull eggs. This method is based on a simple two-step sample extraction followed by liquid chromatography–electrospray ionization(+)-tandem mass spectrometry. Instrumental detection limits and method limits of quantification (MLOQs) among the 12 OPFRs ranged from 0.01 to 0.12 ng/mL and 0.06 to 0.20 ng/g, respectively. The mean OPFR recovery efficiencies of replicate analyses (n = 6) were very quantitative and ranged from 89% to 104%, with the two brominated OPFRs being somewhat lower but reproducible, i.e., 67% and 72%, respectively. Essentially negligible matrix effects were indicated by a standard addition approach that revealed mean percent signal recoveries (n = 5 replicates) of 89–106% for most OPFRs. In the analysis of n = 13 herring gull eggs from the Channel-Shelter Island colony (Lake Huron), tris(2-chloroisopropyl) phosphate (<MLOQ – 4.1 ng/g wet weight, ww), tris(2-chloroethyl) phosphate (<MLOQ – 0.6 ng/g ww) and tris(2-butoxyethyl) phosphate (<MLOQ – 2.2 ng/g ww) were detected and/or quantified.