Bisphenol A and Bisphenol S release in milk under household conditions from baby bottles marketed in Italy

A simple and sensitive validated analytical method based on liquid chromatography coupled to tandem fluorescence (FD) and ultraviolet (UV) spectrophotometry was applied to monitor the presence of bisphenol A and bisphenol S in plastic baby bottles marketed in Italy. The limits of detection (LOD) were 3.75 ng mL^?1 and 80.00 ng mL^?1, and those of quantification (LOQ) were 12.51 ng mL^?1 and 260.00 ng mL^?1 for BPA (FD detection) and for BPS (UV detection), respectively. BPA was found in only four samples, two samples undergone to microwave heating and two samples undergone to bottle warmer heating either at 40°C or at 80°C. Although the quantities of leached BPA were well below the reference dose for daily intake established by the European Food Safety Authority (EFSA) (4.0 µg kg^?1 bw/day), the release of BPA and BPS from these plastic materials should be carefully considered by the government authorities to increase people's awareness on this issue and to protect the most vulnerable population group.     

Occurrence and temporal variations of the xenoestrogens bisphenol A, 4-<Emphasis Type="Italic">tert</Emphasis>-octylphenol,and tech. 4-nonylphenol in two German wastewater treatment plants

GOAL, SCOPE, AND BACKGROUND: The xenoestrogens bisphenol A, 4-tert-octylphenol, and the technical isomer mixture of 4-nonylphenol (tech. 4-nonylphenol) belong to the group of chemicals which are called endocrine disrupters due to their property of causing hormonal dysfunctions in the endocrine system of organisms at very low concentrations. Bisphenol A, 4-tert-octylphenol, and the tech. 4-nonylphenol (mixture of isomers) were determined in water samples collected from the influent and effluent of two German wastewater treatment plants (WWTP) during a long-time sampling period from February 2003 till August 2005 to assess their occurrence and temporal variations in WWTPs. METHODS: The compounds were extracted and concentrated from water by solid-phase extraction (SPE) using Bond Elut PPL cartridges and quantified by use of gas chromatography-mass spectrometry (GC-MS). RESULTS: The influent concentrations were as follows: Bisphenol A < limit of detection of the method (< ldm)--12,205 ng L(-1), tech. 4-nonylphenol < ldm--10,186 ng L(-1), and 4-tert-octylphenol 39-1,495 ng L(-1). The measured effluent concentrations were lower with values in the range of < ldm--7,625 ng L(-1) for bisphenol A, < ldm--14,444 ng L(-1) for tech. 4-nonylphenol, and < ldm--392 ng L(-1) for 4-tert-octylphenol. All target compounds were largely eliminated during the wastewater treatment process. The elimination efficiency varied between 73% and 93%. DISCUSSION: All analytes show highly fluctuating influent concentrations with very high peak concentrations at particular sampling times. The variation of effluent concentrations is by far lower than the variation of influent concentrations. For tech. 4-nonylphenol, a significant temporal concentration variation has been detected with very high concentrations up to the microgram-per-liter level in the time from February 2003 till July 2003 and clearly decreasing concentrations in the time from June 2004 till August 2005. This corresponds well with the implementation of Directive 2003/53/EC (nonylphenol and nonylphenol ethoxylates in the European Union "may not be placed on the marked or used as a substance or constituent of preparations in concentrations equal or higher than 0.1% by mass") from January 2005 on. Bisphenol A is present in the effluent samples in a wide range of concentrations from below the detection limit to high concentrations up to the microgram-per-liter level. For 4-tert-octylphenol, no particular trend of concentration development has been observed. CONCLUSIONS: Combined SPE and GC-MS proved to be an efficient method to identify and quantify polar organic compounds in environmental samples. With respect to the concentrations measured in the present study, bisphenol A sometimes is the prominent compound in influent samples. Neither bisphenol A nor 4-tert-octylphenol or tech. 4-nonylphenol show seasonal variations. However, there was a significant general trend of decreasing concentrations of tech. 4-nonylphenol in influent and effluent samples from both WWTPs which probably reflects the implementing Directive 2003/53/EC. RECOMMENDATIONS AND PERSPECTIVES: Further research is needed to investigate whether the observed decrease of tech. 4-nonylphenol concentrations in German WWTPs since June 2004 will continue further on. The reason for the high effluent concentrations of bisphenol A in only a few samples has to be clarified in further research. The results from this study provide insight into the concentration development of the xenoestrogens bisphenol A, tech. 4-nonylphenol, and 4-tert-octylphenol in WWTPs in the time span between 2003 and 2005.     

Viable chemical recycling of poly(carbonate) as a phosgene equivalent illustrated by the coproduction of bisphenol A and carbohydrate carbonates

Chemical recycling of waste poly(carbonate) (PC) to coproduce bisphenol A (BPA) and carbohydrate carbonates was studied by selecting glycerol (Gly) and glucose (Glu) as model carbohydrates (CHs). In advance of the reaction of PC with CHs, reactions with diphenyl carbonate were examined as a model PC. In dioxane at 100°C using NaOH as catalyst, Gly was converted to cyclic carbonate hydroxymethyldioxolane (HMDO) at 98% and Glu was converted to the dicarbonate (Glu-DC) at 46%, in pyridine, in addition to the production of phenol. Similar treatment of PC with Gly using KOH as a catalyst produced HMDO and BPA at very high yields and treatment with Glu produced Glu-DC and BPA in 38%–42% yields. Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6     

Photocatalytic degradation of endocrine disruptor Bisphenol-A in the presence of prepared CexZn1-xO nanocomposites under irradiation of sunlight

Photocatalytic degradation of Bisphenol A （BPA）, a representative endocrine disruptor chemical, was carried out under irradiation of sunlight in the presence of CexZn1-xO nanophotocatalyst. Cerium （Ce） ions were successfully incorporated into the bulk lattice of ZnO by simple co-precipitation process. The CexZn1-xO composite nanostructures exhibited higher photocatalytic efficiency than pure ZnO in the degradation of BPA under sunlight irradiation and nearly complete mineralization of BPA was achieved. The degradation rate was strongly dependent on factors such as the size and structure of catalyst, doping material concentration, BPA concentration, catalyst load, irradiation time and pH levels. This work suggested that the CexZn1-xO assisted photocatalytic degradation is a versatile, economic, environmentally benign and efficient method for BPA removal in the aqueous environment.     

我国淡水水体中双酚A(BPA)的生态风险评价

双酚A(BPA)对水生生物有多种毒性效应,其中雌激素作用尤为显著.本研究依据BPA对水生生物是否有雌激素效应,把数据分为两类,并通过商值法、安全阈值法、商值概率法以及联合概率曲线法评价了我国淡水水体中BPA对水生生物的风险程度.结果表明,采用4种评价方法得出的结果相近,我国淡水生物对BPA的雌激素效应较BPA对水生生物的其他毒性作用更为敏感;安全阈值法较商值法、商值概率法、联合概率风险评价法误差较小,评价结果更为可信.用安全阈值法评价结果表明,以BPA的雌激素作用为效应终点时,水生生物长期暴露于我国淡水环境中,我国64.70%的淡水水体有导致超过5%的水生生物受到雌激素作用的风险,BPA安全浓度上限为15.72 ng·L-1;而水生物种短期暴露于我国淡水环境中,我国20.43%的淡水水体有导致超过5%的我国淡水生物受BPA雌激素作用的干扰,此时BPA安全浓度上限为2.24×102ng·L-1.     

Stability of the conjugated species of environmental phenols and parabens in human serum

In humans, the metabolism of environmental phenols may include the formation of conjugated species (e.g., glucuronides and sulfates), but the free species—not the conjugated forms—are considered biologically active. Therefore, information on the concentration of these free species in blood or urine could be helpful for risk assessment. Because conjugates could hydrolyze to their corresponding free forms during collection, handling, and storage of biological specimens, information on the temporal stability of the conjugates is of interest. Previously, we reported the temporal stability of urinary conjugates of several environmental phenols, but data on the stability of phenols' conjugated species in serum, albeit critical if concentrations of free and conjugated species are compared, are largely unknown. In the present study, we investigate the stability of the conjugates of four phenols—bisphenol A, benzophenone-3, triclosan, and 2,5-dichlorophenol—and two parabens—methyl paraben and propyl paraben—in 16 human serum samples for 30 days at above-freezing temperature storage conditions (4 °C, room temperature, and 37 °C). These conditions reflect the worst-case scenarios that could occur during the short-term storage of biological samples before their long-term storage at controlled subfreezing temperatures. We found that the percentage of the conjugated species of the four detected compounds (2,5-dichlorophenol, triclosan, and methyl and propyl parabens) in these serum specimens even when stored at 37 °C for at least 30 days did not vary significantly. These preliminary data suggest that the phenols' serum conjugates appear to be more stable than their corresponding urinary conjugates, some of which started to hydrolyze within 24 h under similar storage conditions. The reported stability of these conjugated species in human serum also suggests that the free species are unlikely to have resulted from the hydrolysis of their corresponding conjugates. This information could be important for interpreting the low concentrations of free phenol species detected in serum samples of nonoccupationally exposed populations. To our knowledge, this is the first study to report on the stability of conjugated species in serum, and as such requires replication.     

Oxidation of bisphenol F (BPF) by manganese dioxide

Bisphenol F (BPF), an environmental estrogen, is used as a monomer in plastic industry and its environmental fate and decontamination are emerging concern. This study focused on the kinetics, influencing factors and pathways of its oxidation by MnO₂. At pH 5.5, about 90% of BPF was oxidized in 20 min in a solution containing 100 μM MnO₂ and 4.4 μM BPF. The reaction was pH-dependent, following an order of pH 4.5 > pH 5.5 > pH 8.6 > pH 7.5 > pH 6.5 > pH 9.6. Humic acids inhibited the reaction at low (≤pH 5.5) and high pH (≥pH 8.6) at high concentrations. In addition, metal ions and anions also suppressed the reaction, following the order Mn²⁺ > Ca²⁺ > Mg²⁺ > Na⁺ and HPO₄²⁻ > Cl⁻ > NO₃⁻ ≈ SO₄²⁻, respectively. A total of 5 products were identified, from which a tentative pathway was proposed.     

Hemoglobin (Hb) immobilized on amino-modified magnetic nanoparticles for the catalytic removal of bisphenol A

Catalytic removal of bisphenol A from aqueous solution with hemoglobin immobilized on amino-modified magnetic nanoparticles as an enzyme catalyst was reported. The amino-modified magnetite nanoparticles were firstly prepared by the coprecipitation of Fe²⁺ and Fe³⁺ with NH₃·H₂O and then modified by 3-aminopropyltriethoxysilane. The immobilization process was optimized by examining enzyme concentration, glutaraldehyde concentration, cross-link time, and immobilization time. The optimum conditions for the removal of bisphenol A with immobilized hemoglobin were also investigated. Under the optimality conditions, the removal efficiency of bisphenol A was about 80.3%. The immobilization had a beneficial effect on the stability of hemoglobin and conversions of bisphenol A. According to the proposed breakdown pathway and the intermediates, the enzyme-catalytic removal of bisphenol A by the immobilized hemoglobin is considered to be an effective method.     

1H-NMR-based metabolomic studies of bisphenol A in zebrafish (Danio rerio)

Proton nuclear magnetic resonance (¹H-NMR) spectroscopy was used to study the response of zebrafish (Danio rerio) to increasing concentrations of bisphenol A (4,4′-(propane-2,2-diyl)diphenol, BPA). Orthogonal partial least squares discriminant analysis (OPLS-DA) was applied to detect aberrant metabolomic profiles after 72 h of BPA exposure at all levels tested (0.01, 0.1, and 1.0 mg/L). The OPLS-DA score plots showed that BPA exposure caused significant alterations in the metabolome. The metabolomic changes in response to BPA exposure generally exhibited nonlinear patterns, with the exception of reduced levels of several metabolites, including glutamine, inosine, lactate, and succinate. As the level of BPA exposure increased, individual metabolite patterns indicated that the zebrafish metabolome was subjected to severe oxidative stress. Interestingly, ATP levels increased significantly at all levels of BPA exposure. In the present study, we demonstrated the applicability of ¹H-NMR-based metabolomics to identify the discrete nature of metabolic changes.