Elimination of positive and negative sampling artifacts in particulate organic carbon and PAHs using multi-sorbent coated and uncoated denuders.

Within the scope of this study, two equivalent PM2.5 samplers were designed and developed to eliminate sampling artifacts in the results of atmospheric particulate organic carbon (OC) and particulate polycyclic aromatic hydrocarbons (PAH) caused by volatile organic compounds (VOCs) and gas phase PAH compounds, respectively. A mass loss of less than 10% due to the denuders was observed. Study results showed that if an impregnated denuder is not used, the results of atmospheric particle OC concentrations will be reported with higher values due to positive errors of 53.2 ± 7.23% (median: 52.00%) on average. It was observed that the total error (net error) was still positive, but decreased to an average of 35.1 ± 16.8% (median: 31.0%) after including the negative errors quantified from the backup filter into the calculation. In cases where denuders were not used in the sampling, it was observed that the results with positive errors of 41.0 ± 14.6% (median: 33.8%) on average would be obtained for the total PAHs. Ozone-induced negative interference was the highest in Acenapthylene (28%), followed by Fluoranthane (20%), Phenanthrene (18%), and 15% for Np and Benzo[g,h,i]perylene compounds, relative to their medians. Negative errors of 10% or less were found in all other individual PAH compounds.

An assessment of spatial distribution and atmospheric concentrations of ozone, nitrogen dioxide, sulfur dioxide, benzene, toluene, ethylbenzene, and xylenes: ozone formation potential and health risk estimation in Bolu city of Turkey.

Atmospheric pollutants including ozone, nitrogen dioxide, sulfur dioxide, and BTEX (benzene, toluene, ethylbenzene, and xylenes) compounds were evaluated concerning their spatial distribution, temporal variation, and health risk factor. Bolu plateau where sampling was performed has a densely populated city center, semi-rural areas, and forested areas. Additionally, the ozone formation potentials of BTEXs were calculated, and toluene was found to be the most important compound in ground level ozone formation. The spatial distribution of BTEXs and nitrogen dioxide pollution maps showed that their concentrations were higher around the major roads and city center, while rural-forested areas were found to be rich in ozone. BTEXs and nitrogen dioxide were found to have higher atmospheric concentrations in winter. That was mostly related to the source strength and low mixing height during that season. The average toluene to benzene ratios demonstrated that there was a significant influence of traffic emissions in the region. Although there was no significant change in sulfur dioxide concentrations in the summer and winter seasons of 2017, the differences in the spatial distribution showed that seasonal sources such as domestic heating and intensive outdoor barbecue cooking were effective in the atmospheric presence of this pollutant. The lifetime cancer risk through inhalation of benzene was found to be comparable with the limit value (1 × 10-6) recommended by USEPA. On the other hand, hazard ratios for BTEXs were found at an acceptable level for different outdoor environments (villages, roadside, and city center) for both seasons.

Source identification of exhaust and non-exhaust traffic emissions through the elemental carbon fractions and Positive Matrix Factorization method.

Our study implies the importance of exhaust and non-exhaust emissions in a highway road tunnel, which is crucial to assess their impacts on air quality, human health, climate and developing functional methods for controlling. The total suspended particulates (TSP) and road dust (RD) samples were collected by PUF samplers and manually sweeping, respectively. Campaigns were performed in the summer and winter of 2014 in a highway road tunnel in Bolu, Turkey. Chemical analyses were presented to characterize the contents of organic carbon (OC) fractions (OC1,2,3,4), elemental carbon (EC) fractions (EC1,2,3,4,5,6), polycyclic aromatic hydrocarbons (PAHs) and metals (Al, Ba, Ca, Cu, Mg, Mn, Pb, Sr, Cr and Fe) in the collected TSP and RD samples. Positive matrix factorization (PMF) and orthogonal (Deming) regression analysis were applied to find out the exhaust and non-exhaust vehicle emissions of metal and carbonaceous species in the tunnel. The results showed that the identified source profiles included resuspended road dust (43%), non-exhaust emissions (37%), diesel exhaust emissions (13%), and gasoline exhaust emissions (7%). The relationship between emission markers of metal species and EC carbon fractions was supported by correlation studies. Among these EC fractions, EC4 and EC2 were the most abundant fractions in aerosol and RD samples, respectively and so they highly represented the diesel and non-exhaust emissions. Besides, the EC1 fraction was the indicator of gasoline-fueled emissions. Lower EC1 and higher soot-EC contribution obtained in tunnel aerosol (AS) samples showed the dominance of diesel-fueled vehicles in the tunnel. The data represented herein would help to identify the characteristic of vehicle emissions.

Computational investigation of molecular structures, spectroscopic properties and antitumor-antibacterial activities of some Schiff bases.

Molecular structures, spectroscopic properties (IR, 1H NMR and 13C NMR, UV-VIS), molecular electrostatic potential maps and some molecular properties (ionization energy, electron affinity, energy gap, hardness, electronegativity, electrophilicity index, static dipole moment and average linear polarizability) of three Schiff bases which are 2-((ethylamino)methyl)-6-methoxyphenol (HL1), 2-((ethylamino) methyl)-6-methylphenol (HL2) and 2-((ethylamino)methyl)-6-chlorophenol (HL3) were computed at B3LYP/6-31G(d) level in aqueous phase. The effects of methoxy, methyl and chloro substituents on Schiff bases were examined and it was found that the electron donating property of methyl and chlorine substituents was higher than the methoxy substituent. In order to investigate the antitumor activities of Schiff bases were docked against the breast cancer (MCF7) cell line. Molecular docking results were compared with antitumor standard 5-fluorouracil. Antitumor activity of HL2 and HL3 molecule was found to be higher than HL1 against MCF-7 cell line. In addition, in order to predict the antibacterial activities of Schiff bases were docked against the Mycobacterium tuberculosis (H37Rv) cell line. Docking results were compared with the antibacterial reference N-(salicylidene)-2-hydroxyaniline. Antibacterial activity of HL2 and HL3 molecules was found to be higher than HL1. It is estimated that the binding of the electron donating group to the ortho position of the hydroxyl group in studied Schiff bases increases both antitumor and antibacterial activity.

Structural, spectral characterization and molecular docking analyses of mer-ruthenium (II) complexes containing the bidentate chelating ligands.

In this study, we analyzed some monofunctional Ru (II) complexes containing chlorine, bromine and fluorine atoms around the central atom. The best calculation level among HF, B3LYP and M062X methods for [Ru (Cl-Ph-tpy)(NN)X]+ (X = F, Cl, Br) was determined in the light of Benchmark analysis and according to this analysis results, the best level is shown as B3LYP-LANL2DZ/6-31G(d). In addition to this, the spectroscopic data (IR, NMR and UV-Vis) were also obtained in agreement with experimental results. The tendency of anticancer activity and structural activity relationship (SAR) parameters are predicted with some quantum chemical methods. Surface and contour diagrams, as well as electron densities on mentioned complexes were interpreted through theoretically obtained results. Finally, the anticancer activity tendency of the relevant complexes on the human cervical carcinoma cell line (ID: 1 M17) is supported by molecular docking calculations.

Investigation of structural, electronic properties and docking calculations of some boron complexes with norfloxacin: A computational research.

Quantum chemical calculations are performed over BF2R (1), B(NO)2R (2), B(CN)2R (3) and B(CH3)2R (4) [R: 1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylate]. Mentioned boron complex with fluorine atoms which is BF2R are optimized at HF/6-31+G(d), B3LYP/6-31+G(d) and M062X/6-31+G(d) level and the best level is determined by comparison of experimental and calculated results. The best calculation level is determined as M06-2X/6-31+G(d) level. The other complexes are optimized at this level. Structural properties, IR and NMR spectrum are examined in detail. Additionally, biological activities of mentioned complexes are investigated by some quantum chemical descriptors (EHOMO, ELUMO, I, A, EGAP, η, σ, χ, CP, ω, N, ΔNmax and S) and molecular docking analyses. The interaction energies for complex (1), (2), (3) and (4) are calculated as -480.1, -443.6, -433.6 and -402.1 kJ mol-1, respectively. As a result, it is found that boron complex with fluorine atoms (BF2R) is the best candidate for anticancer drug.

Computational investigations of trans­platinum(II) oxime complexes used as anticancer drug.

Some platinum oxime complexes are optimized at HF/CEP-31G level which has been reported as the best level for these type complexes in the gas phase. IR spectrum is calculated and the new scale factor is derived. NMR spectrum is calculated at the same level of theory and examined in detail. Quantum chemical parameters which have been mainly used are investigated and their formulas are given in detail. Additionally, selected quantum chemical parameters of studied complexes are calculated. New theoretical IC50% formulas are derived and biological activity rankings of mentioned complexes are investigated.

Structural, spectral, NLO and MEP analysis of the [MgO2Ti2(OPr(i)ⁱⁱ)6], [MgO2Ti2(OPr(i)ⁱ)2(acac)4] and [MgO2Ti2(OPr(i)ⁱ)2(bzac)4] by DFT method.

Quantum chemical calculations are performed on [MgO2Ti2(OPr(i))6] and [MgO2Ti2(OPr(i))2(L)4] complexes. L is acetylacetonate (acac) and benzoylacetonate (bzac) anion. The crystal structures of these complexes have not been obtained as experimentally but optimized structures of these complexes are obtained as theoretically in this study. Universal force field (UFF) and DFT/B3LYP method are used to obtain optimized structures. Theoretical spectral analysis (IR, (1)H and (13)C NMR) is compared with their experimental values. A good agreement is found between experimental and theoretical spectral analysis. These results mean that the optimized structures of mentioned complexes are appropriate. Additionally, the active sites of mentioned complexes are determined by molecular electrostatic potential (MEP) diagrams and non-linear optical (NLO) properties are investigated.

Theoretical spectroscopic study of seven zinc(II) complex with macrocyclic Schiff-base ligand.

Seven zinc complexes, which are [ZnL(1)](2+), [ZnL(2)](2+), [ZnL(3)](2+), [ZnL(4)](2+), [ZnL(5)](2+), [ZnL(6)](2+) and [ZnL(7)](2+), are studied as theoretically. Structural parameters, vibration frequencies, electronic absorption spectra and (1)H and (13)C NMR spectra are obtained for Zn(II) complexes of macrocyclic penta and heptaaza Schiff-base ligand. Vibration spectra of Zn(II) complexes are studied by using Density Functional Theory (DFT) calculations at the B3LYP/LANL2DZ. The UV-VIS and NMR spectra of the zinc complexes are obtained by using Time Dependent-Density Functional Theory (TD-DFT) method and Giao method, respectively. The agreements are found between experimental data of [ZnL(5)](2+), [ZnL(6)](2+) and [ZnL(7)](2+) complex ions and their calculated results. The geometries of complexes are found as distorted pentagonal planar for [ZnL(1)](2+), [ZnL(2)](2+) and [ZnL(3)](2+) complex ions, distorted tetrahedral for [ZnL(4)](2+) complex ion and distorted pentagonal bipyramidal for [ZnL(5)](2+), [ZnL(6)](2+) and [ZnL(7)](2+) complex ions. Ranking of biological activity is determined by using quantum chemical parameters and this ranking is found as: [ZnL(7)](2+)>[ZnL(6)](2+)>[ZnL(5)](2+)>[ZnL(3)](2+)>[ZnL(2)](2+)>[ZnL(1)](2+).

Uncertainty of high resolution inductively coupled plasma mass spectrometry based aerosol measurements.

Simultaneous and multi-elemental method was optimized to determine 35 elements in 274 coarse and fine aerosol samples by using HR-ICP-MS. The procedures were validated. Measurement uncertainties of all elements including sampling uncertainties were calculated by applying bottom-up approach. The average recoveries obtained for each element ranged between 79% and 129% using NIST SRM 1648, urban dust. The calculated uncertainties of the analytical methods were between 2.9% and 18% for both sample types. The major contributions to the uncertainty budget come from the calibration curves, repeatability and volume of air.

Atmospheric deposition of polycyclic aromatic hydrocarbons to Izmit Bay, Turkey.

Wet deposition and dry deposition samples were collected in an urban/industrialized area of Izmit Bay, North-eastern Marmara Sea, Turkey, from September 2002 to July 2003. The samples were analyzed for sixteen polycyclic aromatic hydrocarbon (PAH) compounds by using HPLC-UV technique. Wet and dry deposition concentrations and fluxes of PAHs were determined. The results showed that PAH concentrations were high because of industrial processes, heavy traffic and residential areas next to the sampling site. Total dry deposition flux of the fifteen 3-6 ring PAHs was 8.30 microg m(-2)day(-1), with a range of 0.034-1.77 microg m(-2)day(-1). The total wet deposition flux of the fifteen 3-6 ring PAHs was 1716 microg m(-2) 11 month(-1), with a range of 10-440 microg m(-2) 11 month(-1). Significant seasonal differences were observed in both types of deposition samples. The winter fluxes of total PAHs were 1.5 and 2.5 times greater than those of the warm period for wet and dry deposition samples, respectively. Factor analysis of dry deposition samples and back trajectory analysis of wet deposition samples were also used to characterize and identify the PAH emission sources in this study.

Source apportionment of trace metals in surface waters of a polluted stream using multivariate statistical analyses.

Surface water samples were collected from ten previously selected sites of the polluted Dil Deresi stream, during two field surveys, December 2001 and April 2002. All samples were analyzed using ICP-AES, and the concentrations of trace metals (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Pb, Sn and Zn) were determined. The results were compared with national and international water quality guidelines, as well as literature values reported for similar rivers. Factor analysis (FA) and a factor analysis-multiple regression (FA-MR) model were used for source apportionment and estimation of contributions from identified sources to the concentration of each parameter. By a varimax rotated factor analysis, four source types were identified as the paint industry; sewage, crustal and road traffic runoff for trace metals, explaining about 83% of the total variance. FA-MR results showed that predicted concentrations were calculated with uncertainties lower than 15%.

Ecological risk assessment using trace elements from surface sediments of Izmit Bay (Northeastern Marmara Sea) Turkey.

The aim of this study was to study ecological risk assessment of trace elements (As, Cd, Cr, Cu, Ni, Pb and Zn) in Izmit Bay surface sediments in the <63 microm fraction. Sediment samples were collected from 8 sites along the north coastline of the bay. Samples were subjected to a total digestion technique and analyzed for major (organic carbon) and minor (As, Cd, Cr, Cu, Ni, Pb and Zn) elements. Sediments heavily contaminated are evaluated by the Sediment Quality Guidelines (SQG) of US EPA. The degree of contamination (Cd) is estimated as very high at each site. Two sets of SQGs, effect range-low/effect range median values and TEL/probable effect level (PEL) values were used in our study. Sediments from the each site are judged toxic when two or more of the PEL values exceed EPA guidelines. Our results are in agreement with previously reported sediment toxicity test results.