Impact of River Water and Bottom Sediment Pollution on Accumulation of Metal(loid)s and Arsenic Species in the Coastal Plants Stuckenia pectinata L., Galium aparine L., and Urtica dioica L.: A Chemometric and Environmental Study.

The role of water and bottom sediment pollution of a river subjected to a strong industrial anthropo-pressure in coastal plants was investigated. The work presented the influence of polluted environment on accumulation of metal(loid)s (including arsenic and its species) in Stuckenia pectinata L., Galium aparine L., and Urtica dioica L. The study provided important information on the contents of organic and inorganic arsenic species in selected plants and their response to heavy metal and arsenic contamination. The As(III), As(V), AB (arsenobetaine), MMA (monomethylarsonic acid), and DMA (dimethylarsinic acid) ions were successfully separated on the Hamilton PRP-X100 column with high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) techniques. The Pollution Load Index and geo-accumulation Index (Igeo) values clearly indicate significant pollution of the examined ecosystem with heavy metals. The chemometric analysis with the concepts of (Dis)similarity Analysis, Cluster Analysis, and Principal Component Analysis helped to visualize the variability of the As species concentrations and to analyse correlations between sampling point locations and analyte contents.

Metal(loid) speciation in a river subjected to industrial anthropopressure: chemometric and environmental studies.

High-performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS) was applied to the speciation of arsenic [As(III), As(V), and AsB (arsenobetaine)], MMA (monomethylarsonic acid), DMA (dimethylarsinic acid), antimony [Sb(III) and Sb(V)], and chromium [Cr(III) and Cr(VI)] in water and bottom sediment samples collected from the urban Bytomka River (Poland). The main objective of the study was the research of As, Cr and Sb species in the Bytomka River, as well as the simplified three-stage sequential chemical extraction of bottom sediments according to the Institute for Reference Materials and Measurements (BCR). The contents of V, Mn, Co, Ni, Cu, Zn, Rb, Sr, Ag, Cd, Te, Ba, Tl, Pb, Fe, Ga, and U in the water and bottom sediments were tested using the ICP-MS technique. The risk assessment code (RAC) indicated a medium risk for As and a high risk for Sb to the environment. Sequential chemical extraction of bottom sediments showed that As and Cr were strongly demobilized. Sb was mainly bound with the ion-exchange fraction and posed a serious threat to the environment. Chemometric analysis with the (dis)similarity analysis and principal component analysis (PCA) allowed for visualization of the variability and correlations of the analyzed elements.

Chemometric and environmental assessment of arsenic, antimony, and chromium speciation form occurrence in a water reservoir subjected to thermal anthropopressure.

In the study, arsenic, antimony, and chromium concentrations and selected physicochemical parameters in water and sediment samples from the thermal anthroporessure subjected Rybnik Reservoir (Poland) were determined. As(III), As(V), Sb(III), and Sb(V) ions were successfully separated on Dionex IonPac AS7 column, and Cr(III) and Cr(VI) on Dionex IonPac AG7 column. The obtained limits of detection were 0.18, 0.22, 0.009, 0.012, 0.11, and 0.17 µg/L, respectively. Water and bottom sediment samples were collected monthly at three-point transect between January and November 2013. The As(III) and Sb(III) speciation forms dominated in the bottom water, and Cr(VI) concentration in the bottom water was twice as high as the value measured for the surface water. The oxidized arsenic, antimony, and chromium forms dominated in the bottom sediments in the heated water discharge zone of the Rybnik Power Plant. The location of sampling point had a significant influence on the observed transformations and contents of the analyzed speciation forms. The chemometric analysis coupled with the dissimilarity analysis and principal component analysis helped to visualize the variability in the concentrations of the element speciation forms within the researched period and analyzing correlations.

A new concept for variance analysis of hyphenated chromatographic data avoiding signal warping.

Analysis of variance of chromatographic data is usually performed on the peak table or on entire chromatograms. These two data forms require signal pretreatment. Peak table requires peak detection, their standards and quantification, and the second form of data organization requires warping of the studied chromatograms to eliminate the observed peak shifts, which occurs due to minor variations in chromatographic conditions. In our study, a new form of data representation well suited for chromatographic data originating from multi-channel detection is proposed. It requires neither warping of chromatograms, nor peak detection. Its principles and performance are demonstrated for a real data set (being a part of a larger research project initiated to characterize the infusion of fermented rooibos herbal tea in terms of phenolic composition and antioxidant activity). As the method of choice for the analysis of data variation, the Multiple Analysis of Variance applied to the pairwise data representation was chosen.

Non-parametric multivariate analysis of variance in the proteomic response of potato to drought stress.

Spot detection is a mandatory step in all available software packages dedicated to the analysis of 2D gel images. As the majority of spots do not represent individual proteins, spot detection can obscure the results of data analysis significantly. This problem can be overcome by a pixel-level analysis of 2D images. Differences between the spot and the pixel-level approaches are demonstrated by variance analysis for real data sets (part of a larger research project initiated to investigate the molecular mechanism of the response of the potato to drought stress). As the method of choice for the analysis of data variation, the non-parametric MANOVA was chosen. NP-MANOVA is recommended as a flexible and very fast tool for the evaluation of the statistical significance of the factor(s) studied.

6-Chloro-2-oxindole: X-ray and DFT-calculated study.

The molecule of the title compound (systematic name: 6-chloroindolin-2-one), C(8)H(6)ClNO, is almost planar, with a dihedral angle of 1.13 (9)° between the planes of the constituent pyrrolidine and benzene rings. Centrosymmetric dimers are formed in the crystal structure by N-H···O hydrogen bonds, and these dimers are additionally linked by Cl···Cl and C-H···O interactions. Density functional theory (DFT) calculations at the B3LYP/6-31 G(d,p) level of theory were used to optimize the molecular structure and the geometry was best reproduced by optimization of two interacting molecules. The bond orders in the molecule, estimated using the natural bond orbitals (NBO) formalism, are consistent with the observed bond lengths. In particular, the contribution of the lone pair of electrons on the N atom to the N-C bond in the N-C=O group is revealed. The measured IR spectrum of the compound shows a red shift of the N-H stretching frequency compared with the free molecule, due to the formation of the hydrogen bonds.

Influence of mixed cationic-nonionic surfactant systems on the spectral properties of C.I. Mordant Blue 29 and its complexes with iron(III).

Interactions of the anionic form of C.I. Mordant Blue 29 with cationic and nonionic surfactants have been studied by absorption spectroscopy. The dye interacts strongly with oppositely charged surfactants in the pre-micellar concentration range with an accompanying change in its spectral properties, while its interaction with the polyoxyethylene group of nonionic surfactants does not have such remarkable effects. In ternary mixtures, however, the influence of the polyoxyethylene group on the optical properties of C.I. Mordant Blue 29-tetradecyltrimethylammonium bromide and C.I. Mordant Blue 29-octadecyltrimethylammonium chloride systems is quite different. In addition, the influence of the interaction between the HL(3-) form of C.I. Mordant Blue 29 and the surfactants on the formation of chelate complexes with iron(III) has been studied. The optimized structures of Fe-Mordant Blue 29 complexes are also reported herein. Geometries have been calculated by the Hartree-Fock method with the cc-pVDZ basis set.

Excited and ionized states of the ozone molecule with full triples coupled cluster methods.

The role of connected triple excitations in coupled cluster (CC) calculations of vertical excitation energies, ionization potentials, and the electron affinity of the ozone molecule is evaluated. The equation of motion (EOM) and Fock space (FS) multireference CC approaches with full triples have been used in the calculations. The effect of the T(3) and R(3) operators significantly improve the EOM CCSD results for all considered quantities. A similar behavior is observed in the case of the FS-CC calculations. The FS-CC calculations with full triples have been obtained only for the intermediate Hamiltonian realization of the FS approach as the standard formulation diverges. The latter results are rigorously linked, and less expensive since smaller matrices are diagonalized.