Compounds adsorbed onto PM10 in the air near the cement plant were determined. Several side reactions that occur in the hot flue gas stream at the same time as the actual main reactions are also ...possible. This leads to the formation of traces of organic nitrogen compounds. For the GC/MS determination of polar organic compounds silylation as a derivatization method was used. Organic compounds detected are derivatives of sugars, sugar alcohols, and mono-, di- and tri-carboxylic acids. The composition is characteristic for pollution of the urbane atmosphere. Nitrogen organic compounds formed during the urea thermolytic process in hot cement kiln gases represent parabanic acid, 5-hydroxyhydantoin, 4,5-dihydroxyhydantoin, 5-oxoproline, and cyanuric acid. The inorganic part of aerosols detected includes oxyanions of sulfamic acid, sulfate, sulfite, phosphate, and vanadate(V) with ammonium as a cation. Chemical compositions of particles are crucial to assess the health impacts since the biological responses to aerosols are not always linked with major constituents but rather with toxicologically potent minor components.
Objective To evaluate whether urinary bisphenol A (BPA) levels in men adversely influence semen quality and embryo development after medically assisted reproduction. Design Prospective, cohort study. ...Setting University-based tertiary care center. Patient(s) A total of 149 couples undergoing their first or second IVF or intracytoplasmic sperm injection (ICSI) procedure. Intervention(s) None. Main Outcome Measure(s) Semen quality and embryo development parameters until the blastocyst stage after the IVF or ICSI procedure. Result(s) Bisphenol A was detected in 98% (n = 146) of the samples with 0.1 ng/mL limit of detection. The geometric mean BPA concentration was 1.55 ng/mL. After the adjustment for potential confounders using linear regression models, an increase of natural logarithm transformed urinary BPA concentration was associated with lower natural logarithm transformed sperm count (β = −0.241, 95% confidence interval CI −0.470 to −0.012), natural logarithm transformed sperm concentration (β = −0.219, 95% CI −0.436 to −0.003), and sperm vitality (β = −2.660, 95% CI −4.991 to −0.329). The embryo development parameters from oocyte fertilization to the blastocyst formation stage were not affected by BPA exposure. Conclusion(s) Urinary BPA concentrations in male partners of subfertile couples may influence semen quality parameters, but do not affect embryo development up to the blastocyst stage after medically assisted reproduction.
The aim of this research was to determine how best to utilize two environmentally challenging types of waste: sewage sludge, and a particular type of waste ash, biomass ash, which is obtained from ...biomass combustion processes. The results of the performed research have shown that liquid sewage sludge can, in fact, be successfully stabilized with biomass ash, so that a stable composite material can be obtained, having a compressive strength within the range between 0.5 to 2.5 MPa, with “Controlled Low-Strength Material” properties. During the stabilization process, the microbial activity of sewage sludge is inhibited, due to raised pH levels and temperatures. Analysis of the chemical composition of water leachates from samples of the composite showed that it is inert, and thus does not pose a threat to the environment. The observed decrease, over time, in the concentrations of the pollutants indicated that the latter are immobilized in the hydrated matrix, due to the formation of new hydration products, i.e. mono- and hemi-carboaluminate and Friedel's salt, and changes associated with pore diameter and distribution. The addition of selected types of recycled aggregates, to the above-described composite material was also investigated, and it was found that a useful material having similar properties could be obtained. This means that such composite materials could be used as low flow material or back fill, road base stabilization material and bedding material for pipes and cables, as well as for daily or intermediate landfill covers. From the point of view of sustainable development, this kind of waste management presents an optimum – zero waste solution, since it results in the cleaner production, while preserving natural resources, reducing CO2 emissions, and lowering the costs of sewage sludge management.
•Novel composites made of sewage sludge and biomass ash were studied.•They can be used for specific purposes in construction.•The environmental acceptability of the composites was demonstrated.•A cleaner – zero waste solution for sewage sludge and biomass ash is achieved.
Phytochemical investigations of different species of Lamiaceae family (rosemary-Rosmarinus officinalis L., sage-Salvia officinalis L., winter savory-Satureja montana L., clary sage-Salvia sclarea L. ...and sticky sage-Salvia glutinosa L.), using gas chromatography and mass spectrometry (GC-MS) were performed. The studies were focused on oleanolic, betulinic and ursolic acid. Since oleanolic and ursolic acid are position isomers with very similar structures, the difficulties in their separation and identification have been reported by several authors. However, both compounds can be well distinguished by order of elution during gas chromatography and by intensities of the fragment ion signals in their mass spectra, where the retro-Diels-Alder reaction was primarily observed. A combination of ultrasonic extraction, solid phase extraction, size exclusion chromatography, trimethylsilylation, and GC-MS resulted in simultaneous separation, identification and quantification of the mentioned compounds. The compounds have been identified by retention time and comparison of mass spectra with those of pure standards. The mass spectral fragmentation behavior of all three derivatised acids was investigated. The obtained characteristic fragment patterns are discussed in the presented work. Good linearity over the concentration range 1-50 mg L-¹ for all three compounds was confirmed. The correlation coefficients (r ² ) were in the range of 0.9980-0.9983. Quantitative analyses of different Lamiaceae extracts showed that the oleanolic acid content ranged from 0.09 to 0.9% dry weight, content of betulinic acid ranged from traces to 0.6%, and that of ursolic acid varied from 0.09 to 1.6% dry weight.
Organic compounds in atmospheric particulate matterabove Maribor were analysed in 120 samples of PM10 sampled according to the EN 12341:2014 reference method. Organic compounds compositions were ...investigated together with the primary and secondary sources of air pollution. Silylation as derivatisation method was used for the GC/MS determination of volatile and semi-volatile polar organic compounds. Distribution of fatty acids, n-alkanes and iso-alkanes, phthalate esters, siloxanes, different sterols, various sugars and sugar alcohols, compounds of lignin and resin acids, dicarboxylic acids from photochemical reactions, PAHs, organic nitrogen compounds and products from secondary oxidation of monoterpenes were determined. The use of silicone grease for the purpose of lubricating the impact surface of the air sampler caused higher values of gravimetric determination. Solid particles may have been bounced from the surface of a greasy impact plate and re-entrained within the air stream and then collected on a sample filter. The carryover of siloxanes was at least from 5% up to 15% of the accumulated particles weight, depending on ambient temperature. This was the reason that the gravimetric results for determination of PM10 according to the standard EN 12341:2014 were overestimated.
A GC-MS method was successfully applied to measure simultaneously the concentrations of endocrine disrupting compounds (5 dialkyl phthalates, 9 phthalate monoesters, 3 alkylphenols and bisphenol A) ...in 136 male urine samples. In the present study the method was validated and concentrations of EDCs were determined. The results were compared with results from other studies. Correlations between endocrine disrupting compounds and also correlations of endocrine disrupting compounds with two semen quality parameters are presented and evaluated. Significant positive correlations were found between almost all the endocrine disrupting compounds. The parameter sum of DEHP (SUM DEHP) was positively correlated to all the endocrine disrupting compounds but negatively to two semen quality parameters. Negative correlations between the endocrine disrupting compounds and the semen quality parameters could indicate that endocrine disrupting compounds could cause reproductive problems by decreasing the semen count and quality. This research will have helped to evaluate human exposure to endocrine disrupting compounds.
Nonylphenols (NP) possess estrogenic activities and may cause increased risk of cancerous and reproductive abnormalities in several living organisms. Despite their harmful nature, NPs are used as ...additives in food packaging material, especially plastic, which is the main food contact material in today's packaging landscape. According to the fact that food packaging is one of the major potential food contaminant sources regarding NPs, there is a need for more information on identifying and quantifying of these chemicals when migrating into food. Seventeen plastic films for food packaging were analyzed for the presence of NPs; nine of them were plastic films for deep freeze food packaging. We determined and quantified NPs by Gas Chromatography-Mass Spectrometry (GC-MS) using the internal standard method. All plastic films for deep freeze food packaging contained NPs within a concentration range from 11.9 to 43.7 mg/kg. We also studied the migration of NPs from three of the plastic films for deep freeze food packaging into food simulants. The migration of NPs from these plastic films into 95% ethanol and 10% ethanol was higher than the amount migrating into distilled water or 3% acetic acid.
The main objective of our study was to obtain seed cultures for enhancing the transformation of polychlorinated biphenyls (PCBs) in contaminated soil of the transformer station in Zadar, Croatia, ...damaged during warfare activities in 1991. For enrichment, six soil samples were collected from different polluted areas and microcosm approach, stimulating the growth of biphenyl-degrading bacteria, was employed. Enrichment experiments resulted in the selection of two fast growing mixed cultures TSZ7 and AIR1, originating from the soil of the transformer station and the airport area, respectively. Both cultures showed significant PCB-degrading activity (56 to 60 % of PCB50 mixture was reduced after a two-week cultivation). Furthermore, the cultures displayed similar PCB-degrading competence and reduced di-to tetrachlorobiphenyls more effectively than penta- to heptachlorobiphenyls. Strain Z6, identified as Rhodococcus erythropolis, was found to be the only culture member showing PCB-transformation potential similar to that of the mixed culture TSZ7, from which it was isolated. Based on the metabolites identified in the assay with the single congener 2,4,4'-chlorobiphenyl, we proposed that the strain Z6 was able to use both the 2,3-and 3,4-dioxygenase pathways. Furthermore, the identified metabolites suggested that beside these pathways another unidentified pathway might also be active in strain Z6. Based on the obtained results, the culture TSZ7 and the strain Z6 were designated as potential seed cultures for bioremediation of the contaminated soil.
The influence of aluminium cation as a strong electrophilic centre on the thermolysis of chlorophenols chemisorbed on Al(OH)
3 surface was investigated. If thermolysis is carried out at 300 °C the ...spontaneous rupture of the bond between aluminium and oxygen of phenol takes place in the temperature range of 260–280 °C. The thermolysis of chlorophenoxy aluminium compounds occurs through homolytic and heterolytic bond cleavage. In the case of heterolytic cleavage the leaving chlorophenoxy anion causes a simultaneous formation of the aluminium cation, which is the driving force for the rearrangement of the unstable intermediate. By homolytic cleavage of the Al–O bond the chlorophenoxy radical is formed. The isolation of reaction products of the thermolysis of the system Al(OH)
3/2,4,6-trichlorophenol gave five isomers of dimeric compounds of resonance stabilised 2,4,6-trichlorophenoxy radical. The compounds are stable in nonaqueous, aprotic solution, but they are very sensitive to acid catalysis. They quickly transform into aromatic hydroxydiphenyl ethers. The process of dechlorination and aromatisation of cyclohexadienone dimers gives PCDD/PCDF.
The objective of this work is to acquire a better understanding of the gas-phase thermolysis of volatile chlorophenoxyaluminum compounds and to clarify the thermolysis on the fly ash chemisorbed ...chlorophenols. The purpose of this work was to elucidate the mechanism of the thermolysis of 3-chlorophenol chemisorbed on the surface of amorphous aluminum oxide or hydrated aluminum oxide. This is an example of the fly ash mediated surface catalysis reaction where 3,3′-dichlorodiphenylether and three derivates of dichloro-hydroxy-diphenyls are formed as the main thermolysic products. The proposed formation mechanism of 3,3′-dichlorodiphenylether and dichloro-hydroxy-diphenyls isomers is based on the dimerisation of the resonance stabilised 3-chlorophenoxy radical with the 3-chlorophenyl radical, which is formed by the expulsion of CO
2 in the reaction of CO with the 3-chlorophenoxy radical. In this work some electronic and structural properties of aluminum-3-chlorophenolate intermediates are discussed. The results support and offer explanation for the previously suggested mass spectrometric fragmentation pathways and the mechanism of thermolysis. The influence of A1 atom as catalyst is explicitly provided for in the computational model.
PDF
