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1.
Environ Res ; 194: 110502, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33221310

RESUMO

Parabens are antimicrobial preservatives used in a wide range of consumer products such as personal care products, cosmetics, pharmaceuticals, and food. Consequently, the general population is ubiquitously exposed to these substances via dermal absorption, ingestion, and inhalation. Parabens promote estrogenic activity and are hence under assessment as endocrine disrupting substances. Urine samples from 3- to 17-year-old children and adolescents (N = 516) living in Germany were analysed for concentrations of nine parabens in the population representative German Environmental Survey for Children and Adolescents 2014-2017 (GerES V). Detection rates and urinary concentrations of the parabens decreased with increasing length of the alkyl chain. Methyl paraben was quantified in 97% of the samples with a geometric mean (GM) concentration of 7.724 µg/L (6.714 µg/gcreatinine), ethyl paraben was quantified in 69% (GM: 0.943 µg/L and 0.825 µg/gcrea), and n-propyl paraben in 31% (GM: 0.563 µg/L and 0.493 µg/gcrea). Concentrations of iso-propyl paraben, butyl paraben, iso-butyl paraben, and benzyl paraben were below the limit of quantification in most samples. Pentyl paraben and heptyl paraben were not detected in any of the samples. Paraben concentrations in urine were found to be associated with frequent usage of leave-on personal care products and cosmetics. Cumulative exposure to parabens (back-calculated daily intakes, expressed as hazard index) was found to be on a level raising concern in up to 14% of the population, mainly driven by n-propyl paraben, and depending on the level of conservativeness and point-of departures used for calculation.


Assuntos
Poluentes Ambientais , Parabenos , Adolescente , Monitoramento Biológico , Criança , Pré-Escolar , Exposição Ambiental/análise , Monitoramento Ambiental , Alemanha , Humanos , Parabenos/análise
2.
Inorg Chem ; 55(4): 1837-42, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26845512

RESUMO

To investigate the effect of X in ambiphilic compounds BiX(o-PPh2-C6H4)2, PBiP-X, on metallophilic Pt-Bi interactions in its PtCl2 complexes two new derivatives PBiP-Me and PBiP-C6F5 were synthesized. Reaction with dichloro(1,5-cyclooctadiene)platinum(II) led to the platinum(II) complexes [PtCl2(PBiP-Me)], 3, and [PtCl2(PBiP-C6F5)], 4, which together with the halide [PtCl2(PBiP-Cl)], 2, reported previously, establish a series of related PBiP-X complexes differing only in X. This could be complemented by accessing [PtCl2(PBiP-OTf)], 5, through the reaction of 2 with AgOTf. Analysis of the geometrical and electronic structures of these complexes revealed that in all cases the platinum(II) centers act as donors (through their filled d(z(2)) orbitals) to the bismuth(III) centers (possessing σ*(Bi-X)/6p acceptor orbitals). The strength of these interactions increases with increasing electron-withdrawing character of X, which supports the conceptual approach in constructing this new class of compounds.

3.
Angew Chem Int Ed Engl ; 51(20): 4989-92, 2012 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-22473583

RESUMO

Noble metals meet a heavyweight: A pincer ligand brings together bismuth with gold and platinum, so that metallophilic interactions are established. According to DFT calculations, these interactions contain dominant metal→bismuth contributions.

4.
Sci Total Environ ; 763: 144615, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33383503

RESUMO

Exposure to environmental phenols such as bisphenol A, benzophenones, 2-phenylphenol, triclosan, and triclocarban is of concern, because of their endocrine disrupting properties and broad application in consumer products. The current body burden of the 3-17-year-old population in Germany to these substances was assessed in first-morning void urine samples (N = 515-516) collected within the population-representative German Environmental Survey for Children and Adolescents 2014-2017 (GerES V). Bisphenol A was the most prominent phenol analysed here, ubiquitously found in almost all samples with a geometric mean (GM) concentration of 1.905 µg/L (1.669 µg/gcreatinine) and a maximum (MAX) urinary concentration of 399 µg/L. Benzophenone-3 and benzophenone-1 were quantified in 35% and 41% of the samples. GM was below the limit of quantification (LOQ) for benzophenone-3 and 0.559 µg/L (0.489 µg/gcrea) for benzophenone-1, MAX concentrations were 845 µg/L and 202 µg/L, respectively. In 16% of the samples triclosan was found in quantifiable amounts resulting in a GM below LOQ and a MAX concentration of 801 µg/L. Benzophenone-8, 2-phenylphenol and triclocarban were quantified in none or only 1% of the samples. Benzophenone-1 and -3 concentrations were found to be associated with frequent application of personal care products. A comparison with the previous cycle of the survey, GerES IV (2003-2006), showed a decrease of urinary bisphenol A concentrations, mainly in young children. Despite this decrease, the concentration of bisphenol A exceeded the human biomonitoring (HBM) value HBM-I of 0.1 mg/L in 0.11% of the samples. For triclosan, all urinary concentrations were well below the HBM-I value of 2 mg/L. To minimise environmental health risks, it is therefore necessary to maintain a further declining trend for bisphenol A and continue monitoring the exposure to environmental phenols, as well as to monitor substitutes such as bisphenol F and S.


Assuntos
Poluentes Ambientais , Triclosan , Adolescente , Compostos Benzidrílicos , Monitoramento Biológico , Criança , Pré-Escolar , Exposição Ambiental/análise , Monitoramento Ambiental , Alemanha , Humanos , Fenóis
5.
Chem Commun (Camb) ; 47(38): 10794-6, 2011 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-21892472

RESUMO

Reaction of [Cp(2)MoH(2)] with bismuth allyloxide, [Bi{OCH(CH(3))CH==CH(2)}(3)], gave rise to an extended octanuclear complex wherein two cyclic Mo(2)Bi(2) units composed of four Mo-Bi bonds are linked by a Bi-Bi bond. The fact that the construction of such an assembly could be accomplished only in the case of a monomethylation of the parent allyl residue demonstrates a subtle substituent effect.

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