Identification of a novel C10H6N2Br4Cl2 heterocyclic compound in seabird eggs. A bioaccumulating marine natural product?

A novel brominated and chlorinated compound, C10H6N2Br4Cl2, bioaccumulating in seabird eggs was identified and characterized by low- and high-resoluti on electron impact ionization (EI), electron capture negative ionization (E CNI), and ammonia positive chemical ionization (PCI) mass spectrometry. Thi s compound is the major congener of a series of four hexahalogenated specie s. The major congener was determined in egg samples from Leach's storm; pet rel, rhinoceros auklet, glaucous-winged gull, and black-footed albatross fr om the Pacific coast area; Leach's storm-petrel, Atlantic puffin, and herri ng gull from the Atlantic coast; and herring gull from the Great Lakes usin g GC-ECNI-MS. The concentrations of C10H6N2Br4Cl2 in the Pacific Ocean samp les ranged from 1.8 to 140 ng/g (wet weight), and were significantly higher than the Atlantic Ocean samples (p = 0.037). The Pacific Ocean samples con tained levels of C10H6N2Br4Cl2 approximately 1.5-2.5 times higher than in t he Atlantic Ocean samples of the same or ecologically similar species. The compound was not detected in any of the samples from the Great Lakes. The P acific Ocean offshore surface feeders had the highest concentrations (34-14 0 ng/g) when compared to the other samples (0.61-5.6 ng/g). Its strictly ma rine occurrence and relatively high nitrogen content indicate that C10H6N2B r Cl-2 probably is a marine natural product, found at highest concentration s in the Pacific Ocean surface feeding birds. A possible structure of C10H6 N2Br4Cl2 is 1,1'-dimethyltetrabromoclichloro-2,2'-bipyrrole.