Occurrence and concentrations of halogenated natural products derived from seven years of passive water sampling (2007-2013) at Normanby Island, Great Barrier Reef, Australia.

Polydimethylsiloxane (PDMS) based passive water samplers deployed at Normanby Island, Great Barrier Reef (Australia) from 2007 to 2013 were analyzed for halogenated natural products (HNPs). Altogether, 38 samples, typically deployed for 30 days, were studied. Five HNPs (Q1, 2'­MeO-BDE 68, BC-10, 2,4­dibromoanisole and 2,4,6­tribromoanisole) were detected in all samples. Most samples (>90%) featured 2,2'­diMeO-BB 80, 6­MeO-BDE 47, 2',6­diMeO-BDE 68 and 2,4­dibromophenol. In addition, tetrabromo­N­methylpyrrole (TBMP) was detected in ~80% and Cl6-DBP in ~30% of the samples. Estimated time weighted maximum water concentrations were >150 pg Q1 and 60 pg 2'­MeO-BDE 68 per L seawater. Typically, the concentrations were varying from year to year. Moreover, time weighted average water concentration estimates did not reveal consistent maximum trend levels within a given year. Additional screening analysis via GC/MS indicated the presence of several polyhalogenated 1'­methyl­1,2'­bipyrroles (PMBPs), 1,1'­dimethyl­2,2'­bipyrroles (PDBPs), and 1­methylpyrroles (PMPs) along with four brominated N­methylindoles and several other polyhalogenated compounds at Normanby Island.

Synthesis, structure elucidation, and determination of polyhalogenated N-methylpyrroles (PMPs) in blue mussels.

Polyhalogenated N-methylpyrroles (PMPs) are halogenated natural products (HNPs) recently detected in seagrass, blue mussels, and other marine organisms. In this study, we synthesized 2,3,4,5-tetrachloro-N-methylpyrrole (Cl4-MP), 2,3,4,5-tetrabrominated-N-methylpyrrole (Br4-MP, aka TBMP), and mixed tetrahalogenated (Cl and Br) N-methylpyrrole congeners. Use of one- and two-dimensional 1H and 13C NMR verified the structures of isolated/enriched 3,4-dibromo-2,5-dichloro-N-methylpyrrole (3,4-Br2-2,5-Cl2-MP), 2,3,4-tribromo-5-chloro-N-methylpyrrole (2,3,4-Br3-5-Cl-MP), and 3-bromo-2,4,5-trichloro-N-methylpyrrole (3-Br-2,4,5-Cl3-MP). GC/EI-MS and GC/ECNI-MS mass spectra of the five PMPs were studied with regard to fragmentation pattern and individual responses which were strongly affected by the presence (or absence) of Br in α-position(s). Quantitative solutions of the synthesized standards were used to determine the elution order of isomers and to quantify PMPs in selected blue mussel samples (Mytilus sp.) from the European Atlantic coast (Spain, France), the North Sea (the Netherlands, Germany) and Baltic Sea (Germany). PMPs were detected in all samples and the concentrations ranged between 0.6 and 52 µg/kg lipids with Br4-MP being the most abundant representative of this substance class.

A non-targeted gas chromatography/electron capture negative ionization mass spectrometry selected ion monitoring screening method for polyhalogenated compounds in environmental samples.

RATIONALE: Many organohalogen compounds with adverse environmental properties have been detected in samples from marine ecosystems. Their quantitation is an important task in environmental analytical chemistry. However, the highly selective gas chromatography/mass spectrometry (GC/MS) selected ion monitoring (SIM) methods developed for this purpose only allow the detection of targeted compounds while unscreened compounds remain undiscovered. The detection of all polyhalogenated compounds in a sample requires the application of non-target methods. METHODS: We present a simple quadrupole-based GC/ECNI-MS-SIM method in which the entire high mass range is screened in eight GC runs using three time windows. Recently developed in the GC/EI-MS mode, this approach has now been adapted to the more sensitive GC/ECNI-MS mode. With this method we analyzed a fraction of a dolphin blubber sample from Australia and a sponge sample from the Mediterranean Sea on polychlorinated and polybrominated compounds and compared the results with the corresponding GC/EI-MS measurements. RESULTS: The non-targeted GC/ECNI-MS-SIM chromatograms were clearly structured and hardly showed co-elutions. Altogether, >400 polyhalogenated compounds were detected in both samples. Many of them originated from unknown compounds. Several new or scarcely analyzed compounds could be tentatively identified. Most of the compounds were not detected with the non-target GC/EI-MS-SIM approach (~150 compounds detected). We also developed a two-dimensional plot in which the mass of the monoisotopic peak was plotted over the GC retention time and which was helpful for the identification of isomers. CONCLUSIONS: Since eight GC runs are required per sample, the method is not aimed for routine analysis. It is recommended as an initial screening method for the analysis of new sample matrices or samples from new regions. The non-targeted GC/ECNI-MS-SIM method benefits from the fact that it can be used with standard equipment.

Concentrations of halogenated natural products versus PCB 153 in bivalves from the North and Baltic Seas.

Different halogenated natural products (HNPs) have been reported to occur in marine wildlife, particularly from regions with comparably little contamination with anthropogenic pollutants. The North Sea and the Baltic Sea have been known as a marine site heavily polluted with organohalogen compounds, and especially with polychlorinated biphenyls (PCBs). In this study we wished to determine the current abundance of HNPs in comparison with 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), i.e. the major PCB congener in marine biota. For this purpose, forty blue mussels (Mytilus edulis) and oysters (Crassostrea gigas) from seven sites were analyzed on HNPs and PCB 153. Most of the samples contained HNPs in the form of polyhalogenated 1'-methyl-1,2'-bipyrroles (PMBPs including Q1) and the mixed halogenated compound MHC-1. In addition we determined several polyhalogenated 1,1'-dimethyl-2,2'-bipyrroles (PDBPs), 2,3,4,5-tetrabromo-N-methylpyrrole and several novel homologs, as well as polybrominated N-methylindoles. The occurrence of these HNP groups were considerably different in the samples from different regions with varying sum concentrations up to 1930 µg/kg lipids in blue mussels from Heligoland (North Sea) and much lower concentrations in samples from the Baltic Sea (up to 13 µg/kg lipids). The concentrations of HNPs varied by two orders of magnitude, compared to a factor of 10 for PCB 153, suggesting that HNPs are more spatially (and perhaps temporally) variant than POPs. In the North Sea region Heligoland, HNPs were more abundant than PCB 153.

Discovery and widespread occurrence of polyhalogenated 1,1'-dimethyl-2,2'-bipyrroles (PDBPs) in marine biota.

Polyhalogenated 1,1'-dimethyl-2,2'-bipyrroles (PDBPs) are halogenated natural products (HNPs) previously shown to bioaccumulate in marine mammals and birds. Since their discovery in 1999, six hexahalogenated and a few lesser halogenated congeners have been identified in diverse marine mammal samples. Here we report the identification of 17 additional hexahalogenated PDBPs in the blubber extract of a humpback dolphin (Sousa chinensis) from Queensland, Australia. Thirteen of these new PDBPs were also detected in an Australian sea cucumber (Holothuria sp.). Additional samples were also tested positive on several new PDBPs, including an Australian venus tuskfish (Choerodon venustus) as well as a white whale (Delphinapterus leucas) and a sperm whale (Physeter macrocephalus) from the Northern Hemisphere. GC/ECNI-MS-SIM quantification of the molecular ions was carried out with the help of synthesized standards. The sum concentration of PDBPs was 1.1 mg/kg lipid in the humpback dolphin and 0.48 mg/kg lipid in the sea cucumber.