PCBs in Older Buildings: Measuring PCB Levels in Caulk and Window Glazing Materials in Older Buildings.

A method for the determination of polychlorinated biphenyls (PCBs) in caulk and glazing materials was developed and evaluated by application to a combination of 36 samples of caulk and glazing materials, from four schools in the northeastern area of the United States. Quality control analysis showed a range of 45 to 170% for spike recovery from the various samples and a range of 10.9 to 20.1% difference in precision among replicates. The result for the samples analyzed showed that three of the four schools sampled contained caulking and glazing materials with levels of PCBs >50 µg/g (range 54.6 µg/g to 445,000 µg/g). Across the four schools, 24% of collected caulk and glazing samples contained elevated PCB levels relative to the U.S. Environmental Protection Agency's (EPA) bulk product waste criterion of 50 µg/g under "The Frank R. Lautenberg Chemical Safety for the 21st Century Act." The PCBs determined in the samples, exhibited characteristic chromatographic patterns similar to those of Aroclors 1242, 1248, 1254, 1260, 1262, and a 1016/1254 mix.

Identification of bound nitro musk-protein adducts in fish liver by gas chromatography-mass spectrometry: biotransformation, dose-response and toxicokinetics of nitro musk metabolites protein adducts in trout liver as biomarkers of exposure.

Ubiquitous occurrences of synthetic nitro musks are evident in the literature. The in vivo analysis of musk xylene (MX) and musk ketone (MK)-protein adducts in trout liver has been performed by gas chromatography-mass spectrometry using selected ion monitoring (GC-SIM-MS). Biotransformation, dose-response and toxicokinetics studies of 2-amino-MX (2-AMX), 2-amino-MK (2-AMK) and 4-amino-MX (4-AMX) metabolites, covalently bound to cysteine amino acids in proteins in fish liver, formed by enzymatic nitro-reduction of MX and MK, have been described. Trouts were exposed to single exposures of 0.010, 0.030, 0.10, and 0.30 mg/g MX and/or MK. Forty-two fish liver samples were collected from exposed- and control-fish subsequent to exposure intervals of 1 day, 3 days, and 7 days and were composited as per exposure schedules and times. Alkaline hydrolysis released bound metabolites from exposed liver composites that were extracted into n-hexane and then concentrated and analyzed by GC-SIM-MS. The presence of the metabolites in liver extracts was confirmed based on agreement of similar mass spectral properties and retention times with standards. In the dose-response study, the maximum adduct formation was 492.0 ng/g for 2-AMX, 505.5 ng/g for 2-AMK and 12588.5 ng/g for 4-AMX in liver at 0.03 mg/g MX and MK fish in 1 day after exposure. For toxicokinetics investigation, the highest amount of the target metabolites was found to be the same concentration as observed in the dose-response study for 1 day after exposure with 0.03 mg/g MX and MK fish and the half-lives of the metabolites were estimated to be 2-9 days based on assumption of first-order kinetics. Average recoveries exceeded 95% with a relative standard deviation (RSD) around 9%, and the limit of detection (LOD) ranged from 0.91 to 3.8 ng/g based on a signal to noise ratio of 10 (S/N=10) could be achieved for the metabolites. No metabolites were detected in the controls and exposed non-hydrolyzed liver extracts. This is the first report on dose-response and toxicokinetics of nitro musk-cysteine-protein adducts in fish liver.

Determination of synthetic musk compounds in sewage biosolids by gas chromatography/mass spectrometry.

A review of sewage sludge regulations and land application practices by the United States National Research Council (2002) recommended development of improved analytical techniques to adequately identify and quantify new chemical contaminants, such as synthetic musk compounds in Class A sewage sludge (i.e., biosolids). This prompted the development of a rugged analytical method using gas chromatography coupled to mass spectrometry to detect this group of organic pollutants in biosolids. In this paper, the term "biosolids" is used interchangeably with "sewage sludge", which is defined in the regulations and used in the statue (Clean Water Act). Samples of Class A biosolids obtained from sewage treatment plants in Los Angeles, California, the City of Las Vegas, Nevada, and also in the form of a commercial fertilizer, were extracted using pressurized liquid extraction technique, subjected to gel permeation chromatography clean-up, and analyzed by GC/MS using the selected ion monitoring mode. The method developed has the potential to detect synthetic musk compounds in complex matrices, may provide accurate data useful in human health and environmental risk assessment, and may be useful in determining the efficacy of municipal sewage treatment plants for removing synthetic musk compounds.

Levels of synthetic musk compounds in municipal wastewater for potential estimation of biota exposure in receiving waters.

We analyzed water samples from the confluence of three municipal sewage treatment effluent streams, surface water, and whole carp (Cyprinus carpio) for synthetic musks for a period of 7-12 months. The lipid content of each fish was determined and compared with the concentration of musks in the whole fish tissue. Enhanced methods were used for water sampling and musk extraction. The data presented here provide insight as to the relationship between concentrations of synthetic musks in the municipal effluent and associated biota. This study confirmed the presence of polycyclic and nitro musk compounds in sewage effluent, Lake Mead water, and carp. The concentrations were found to be considerably lower than previous studies conducted in other countries. This study also provides data for polycyclic and nitro musk compounds, as well as some of the nitro musk metabolites in sewage treatment plant effluent, lake water, and carp.