A highly chlorinated flame retardant, Dechlorane Plus (DP), was detected and identified in ambient air, fish, and sediment samples from the Great Lakes region. The identity of this compound was confirmed by comparing its gas chromatographic retention times and mass spectra with those of authentic material. This compound exists as two gas chromatographically separable stereoisomers (syn and anti), the structures of which were characterized by one-and two-dimensional proton nuclear magnetic resonance. DP was detected in most air samples, even at remote sites. The atmospheric DP concentrations were higher at the eastern Great Lakes sites (Sturgeon Point, NY, and Cleveland, OH) than those at the western Great Lakes sites (Eagle Harbor, MI, Chicago, IL, and Sleeping Bear Dunes, MI). At the Sturgeon Point site, DP concentrations once reached 490 pg/m3. DP atmospheric Concentrations were comparable to those of BDE-209 at the eastern Great Lakes sites. DP was also found in sediment cores from Lakes Michigan and Erie. The peak DP concentrations were comparable to BDE-209 concentrations in the sediment core from Lake Erie but were about 30 times lower than BDE- 209 concentrations in the core from Lake Michigan. In the sediment cores, the DP concentrations peaked around 1975-1980, and the surficial concentrations were 10-80% of peak concentrations. Higher DP concentrations in air samples from Sturgeon Point, NY, and in the sediment core from Lake Erie suggest that DP's manufacturing facility in Niagara Falls, NY, may be a source. DP was also detected in archived fish (walleye) from Lake Erie, suggesting that this compound is, at least partially, bioavailable.

During the analysis of brominated flame retardants in sediment cores taken from Lake Michigan, a group of unknown brominated compounds were observed. To identify their chemical structures, a variety of gas chromatographic mass spectrometric techniques were used. With the help of high-resolution and positive chemical ionization mass spectrometry, the molecular formula of the most abundant congener was established to be C12H5Br4N. On the basis of the electron impact and electron capture negative ionization mass spectra, this chemical was suspected of being a tetrabromocarbazole. The structure was confirmed by comparing the mass spectra and gas chromatographic retention times of an authentic standard of 1,3,6,8-tetrabromocarbazole with those of the most abundant unknown. The other unknown compounds may be other bromocarbazole congeners. The time trend determined by measuring these compounds as a function of depth in the Lake Michigan sediment cores indicated that the concentration of 1,3,6,8-tetrabromocarbazole peaked around 1920-1935. This is the first time that bromocarbazoles have been found in the environment.

Large-volume sample stacking (LVSS) is an effective on-capillary sample concentration method in capillary zone electrophoresis, which can be applied to the sample in a low-conductivity matrix. NaOH solution is commonly used to back-extract acidic compounds from organic solvent in sample Fretreatment. The effect of NaOH as sample matrix on LVSS of haloacetic acids was investigated in this study. It was found that the presence of NaOH in sample did not compromise, but rather help the sample stacking performance if a low pH background electrolyte (BGE) was used. The sensitivity enhancement factor was higher than the case when sample was dissolved in pure water or diluted BGE. Compared with conventional injection (0.4% capillary volume), 97-120-fold sensitivity enhancement in terms of peak height was obtained without deterioration of separation with an injection amount equal to 20% of the capillary volume. This method was applied to determine haloacetic acids in tap water by combination with liquid-liquid extraction and back-extraction into NaOH solution. Limits of detection at sub-ppb levels were obtained for real samples with direct UV detection.

This paper describes a novel method that applies fieldamplified sample injection (FASI) in micellar electrokinetic chromatography (MEKC) with a low pH background electrolyte (BGE). Six phenolic compounds prepared in water or NaOH solution were used as the test analytes. Sample was injected electrokinetically after the introduction of a plug of water. During the injection, the water plug was pumped out of the capillary inlet by the electroosmotic flow, and the phenolic anions migrated very quickly in the direction of the outlet. When the anions reached the boundary between the water plug and BGE, they were neutralized and ceased moving. Thereafter, MEKC was initiated for the separation. This on-line preconcentration method could be conveniently coupled with a liquid-liquid-liquid microextraction procedure, in which a hollow fiber was used as an extraction solvent support to extract the analytes from the water sample. The acceptor phase consisted of 8mM NaOH. After extraction, the extract was analyzed directly by MEKC, as described.

The total concentrations (ΣPBDE) of 15 polybrominated diphenyl ethers, BDEs 17, 28, 47, 49, 66, 71, 85, 99, 100, 138, 153, 154, 183, 190, and 209, and a predominant polybrominated biphenyl (PBB) congener, 2,2´,4,4´,5,5´-polybrominated biphenyl (PBB-153) were determined in six natural matrix Standard Reference Materials (SRM) provided by the National Institute of Standards and Technology (NIST). The ΣPBDE concentrations (±one standard deviation) in SRM 1945 (whale blubber), SRM 1946 (fish tissue), SRM 1947 (fish tissue), and SRM 1974b (mussel tissue) were ±126, 7±79, 3±134, 5, and 7.9±0.2ng/g of wet wt, respectively. The ΣPBDE concentrations were 54±2 and 163±4ng/g of dry wt for SRM 2977 (mussel tissue) and SRM 2978 (mussel tissue), respectively. Among the three kinds of marine animals, mussel tissue had the lowest total concentration of PBDEs. These values can provide an informal reference or benchmark to laboratories who measure these compounds.