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1.
Environments ; 6(2): 15, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31534301

RESUMO

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.

2.
Anal Bioanal Chem ; 407(21): 6481-92, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26077747

RESUMO

The emphasis of this research project was to develop and optimize a solid-phase extraction method and high-performance liquid chromatography-electrospray ionization-mass spectrometry method, such that a linkage between the detection of endocrine-active pharmaceuticals (EAPs) in the aquatic environment and subsequent effects on fish populations could eventually be studied. Four EAPs were studied: tamoxifen (TAM), exemestane (EXE), letrozole (LET), anastrozole (ANA); and three TAM metabolites: 4-hydroxytamoxifen, e/z endoxifen, and n-desmethyl tamoxifen. In aqueous matrices, the use of isotopically labeled standards for the EAPs allowed for the generation of good recoveries, greater than 80 %, and low relative standard deviations (% RSDs) (3 to 27 %). TAM metabolites had lower recoveries in the spiked water matrices: 35 to 93 % in waste/source water compared to 58 to 110 % in DI water. The precision in DI water was acceptable ranging from 8 to 38 % RSD. However, the precision in real environmental wastewaters could be poor, ranging from 15 to 120 % RSD, dependent upon unique matrix effects. In plasma, the overall recoveries of the EAPs were acceptable: 88 to 110 %, with %RSDs of 6 to 18 % (Table 3). The spiked recoveries of the TAM metabolites from plasma were good, ranging from 77 to 120 %, with %RSDs ranging from 27 to 32 %. Two of the TAM metabolites, 4-hydroxytamoxifen and n-desmethyl tamoxifen, were confirmed in most of the environmental aqueous samples. The discovery of TAM metabolites demonstrates that the source of the TAM metabolites, TAM, is constant, introducing a pseudo-persistence of this chemical into the environment.


Assuntos
Disruptores Endócrinos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Cromatografia Líquida , Peixes , Limite de Detecção , Espectrometria de Massas em Tandem
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