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Odumiranjem stabala mijenjaju se stanišne prilike u šumskom ekosustavu, uslijed čega dolazi do promjene mikroklime i mikrobiološke aktivnosti tla. Cilj ovoga istraživanja je utvrditi razlike u mikroklimi staništa te u enzimatskoj aktivnosti šumskog tla u trima šumskim progalama i trima šumskim sastojinama obične jele s rebračom (Blechno-Abietetum Ht. 1950). Od mikroklimatskih elemenata mjerene su temperatura zraka, temperatura tla, relativna vlažnost zraka i volumetrijska vlažnost tla. Za određivanje kemijskih svojstava tla te dehidrogenazne i proteolitičke aktivnosti tala prikupljeni su kompozitni uzorci tla s dubine od 0 do 10 cm. U šumskim progalama utvrđene su značajno više vrijednosti temperatura zraka i tla te značajno niže vrijednosti relativne vlažnosti zraka i volumetrijske vlažnosti tla nego u šumskoj sastojini. Provedenim istraživanjem nisu utvrđene značajne razlike u kemijskim svojstvima tala između šumskih progala i sastojina. Zbog nesignifikantnih promjena kemijskih karakteristika tla, nisu utvrđene značajne promjene u enzimatskoj aktivnosti tala u progalama u odnosu na šumske sastojine. Temperatura zraka i temperatura tla povezane su s dehidrogenaznom aktivnosti tala, dok su temperatura tla i volumetrijska vlažnost tla povezane s proteolitičkom aktivnosti tala u šumskim progalama. Kemijska su svoj­stva tla također imale značajan utjecaj na enzimatsku aktivnost, jer se povećanjem udjela organske tvari, dušika, humusa i ugljika u tlu povećava i enzimatska aktivnost šumskih tala. Najveće korelacije enzimatske aktivnosti i kemijskih svojstava tla utvrđene su za proteolitičku aktivnost šumskih tala. Enzimatska aktivnost šumskih tala bila je najveća na početku vegetacijskog razdoblja u uvjetima optimalne temperature i vlažnosti tla., With the decline of trees, habitat conditions change, resulting in changes in the microclimate and microbiological activity of the soil. The aim of the research is to determine the differences in the microclimate of habitats and in the enzymatic activity of forest soil in three forest gaps and three forest stands of silver fir with hard fern (Blechno-Abietetum Ht. 1950). Of the microclimatic elements, air temperature, soil temperature, relative air humidity and volumetric soil moisture were measured. Composite soil samples from a depth of 0 to 10 cm were collected to determine the chemical properties of the soil and the dehydrogenase and proteolytic activity of the soil. Significantly higher values of air and soil temperatures and significantly lower values of relative air humidity and volumetric soil moisture were found in forest gaps. The research did not reveal any differences in the chemical properties of the soil between forest gaps and stands. Due to insignificant changes in soil chemical characteristics, no significant changes in soil enzymatic activity were found in the gaps in relation to forest stands. Air temperature and soil temperature are related to soil dehydrogenase activity, while volumetric soil moisture is associated with proteolytic soil activity in forest gaps. Soil chemical characteristics also had a significant effect on enzymatic activity. By increasing the share of organic matter, nitrogen, humus and carbon in the soil, the enzymatic activity of forest soils also increases. The highest correlations between enzymatic activity and soil chemical characteristics were found for proteolytic activity of forest soils. The enzymatic activity of forest soils was highest at the beginning of the vegetation period under conditions of optimal soil temperature and soil moisture.

Twenty-six major and trace elements, in the seed and the mesocarp of wild and cultivated rosehips from different locations in Serbia, were quantified by means of inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The cultivated rosehip was investigated for the first time. In both wild and cultivated rosehips, the most abundant elements were K and Ca. Among trace elements, Mn (in both seed and mesocarp); Fe (in seeds); and B, Ba, and Sr (in mesocarp) were quantified in the highest concentrations. The higher content of Cu, K, Mn, P, and S in the seed of cultivated rosehip, as well as Ca, Mg, and Sr in the mesocarp of wild rosehip, was observed, both significant atp lt 0.05. Additionally, differences between the seed and the mesocarp of studied rosehip were noticed in the content of B, Cu, Fe, K, Ni, P, S, Sr, and Ti (p lt 0.05). Nutritional assessment revealed that both wild and cultivated rosehips are a valuable source of essential elements (Ca, Cu, K, Mg, Mn, and P). The absence of toxic and potentially toxic elements additionally contributes to the quality of studied Serbian rosehip. A high impact of factors such as variety, location, as well as their interaction on the content of elements in cultivated rosehip mesocarp and seed was observed. Pattern recognition techniques, principal component analysis (PCA), and hierarchical cluster analysis (HCA) were applied in order to provide insight into similarities among the analyzed samples.

This paper is intended to be a constructive discussion of Fiket et al. (2017, Geostandards and Geoanalytical Research, 41, 123–135), who dealt with the determination of major, trace and rare earth elements in several sediment and soil certified reference materials. In the present author's view, the paper by Fiket et al. (2017) suffers from a lack of reference to several publications in which somewhat similar results had already been reported. The present contribution therefore provides a comparison of previously published results with those of Fiket et al. for the CRMs soil NCS DC 77302 (GBW 07410), stream sediment NCS DC 73309 (GBW 07311), marine sediments MESS‐3 and NCS DC 75301 (GBW 07314) and estuarine sediment IAEA‐ 405. It is argued that this fuller consideration (a) allows critical evaluation of the quality of the results presented by Fiket et al. and (b) highlights the advantages of their work. Finally, attention is drawn to the (possible or real) problems that can arise during simultaneous determination of multiple trace elements.

Water fountains are usually present in the urban public places and often draw the attention of citizens and tourists. Their water is often, in various ways, used by adults and children, but water from fountains is not usually a subject of researchers' interest. This paper describes the analytical procedure and the results of the multi-elemental characterisation of the waters from the selected public water fountains in the city of Zagreb, Republic of Croatia. Twenty-eight chemical elements (Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, P, Pb, S, Sb, Se, Sr, Ti, Tl, V, Zn and Ca, K, Mg and Na) were quantified by means of ICP-AES technique. In addition to the multi-elemental analysis, determination of pH values was performed too. Pearson's correlation coefficients suggest that Al, Cu, Fe, Mn and Pb originate from the plumbing system and their leaching is strongly negatively correlated with the pH values of the tested samples. On the other hand, alkali and alkaline-earth metals as well as Mo, Ti, Zn and B, P and S are most probably of a natural origin in the water samples tested in this study. The results lead to the conclusions that (i) trace and major element content in squirt of a monumental water fountain is analogous to their content in water of the same origin and (ii) a pool of a fountain which is made of a high-quality stone, in the context of the herein performed testings, generally does not affect the quality of water which is contained in it.

Airborne fly ash and related hazardous particles derived from coal combustion contaminate soil and groundwater, negatively affecting ecosystems. The aim of this study was chemical and toxicological evaluation of aqueous extracts of soil collected from the vicinity of a coal-fired Plomin power plant (PPP), using Lemna (Lemna minor L.) bioassay and additional biochemical indicators - photosynthetic pigments, lipid peroxidation, antioxidative enzymes and glutathione. Topsoil samples were collected from distances of 200, 300, 400 and 800 m from the PPP in accordance with the prevailing SW wind direction. Elevated levels of polycyclic aromatic hydrocarbons (up to 15,765 ng L−1) and potentially toxic trace elements were detected in the Plomin soil extracts (PEs) in comparison to control soil extract (CE). Trace elements accumulated in L. minor were mostly in accordance with their concentrations in PEs. The results demonstrate that PEs induced significant growth inhibition and other phytotoxic effects. Those effects can be related to damage caused by increased production of reactive oxygen species and impaired antioxidant levels. The connection among the phytotoxicity, a distribution of analyzed contaminants, and distances from the PPP is clearly established.

Matični supstrat, uz klimu, reljef, organizme i vrijeme, predstavlja jedan od pet glavnih pedogenetskih čimbenika. S pedogeneskog stajališta najvažnija su svojstva matičnog supstrata: mineralni i kemijski sastav, način i intenzitet trošenja te sadržaj biogenih elemenata. Cilj ovog rada je utvrditi utjecaj različitih matičnih supstrata na fizičke i mineralne značajke tla. Na području PP Medvednice na šest različitih litoloških cjelina otvoreno je 80 pedoloških profila: metamorfne stijene – dominantno škriljevci, metamorfne stijene – dominantno filiti, magmatske stijene, pješčenjaci, lapori i lako trošivi vapnenci. Uzorci tla uzeti su po horizontima, a analizirani su oni iz humusnoakumulatinog (A-horizont) i B-horizonta. Određeni su sljedeći parametri: debljina horizonata, dubina profila, udjel skeleta, garnulometrijski sastav tla, postojanost strukturnih mikroagregata i mineralni sastav tla (XRD) metodom rendgenske difrakcije. Rezultati istraživanja pokazuju da postoje statistički značajne razlike između različitih litoloških cjelina za sve promatrane varijable osim debljine horizonata. Najveće dubine tla su povrh laporovitih stijena, a najmanje na dolomitiziranim vapnencima, što je ponajprije uvjetovano načinom trošenja matičnog supstrata. Na svim istraživanim litološkim cjelinama, tla na području PP Medvednice vrlo su postojanih mikroagregata. U odnosu na B-horizont u humusnoakumulativnom horizontu utvrđena je veća postojanost strukturnih mikroagregata. Tla povrh lakotrošivih vapnenaca imaju statistički veći udjel gline i manji udjel krupnog i sitnog pijeska od tla ostalih litoloških cjelina. Za sve litološke cjeline teksturna oznaka najčešće je u rasponu od praškaste do glinaste ilovače, dok je na litološkoj cjelini povrh vapnenaca udjel gline statistički značajno veći, pa je teksturna oznaka u rasponu od praškaste glinuše do glinuše. Litološke cjeline povrh magmatskih i metamorfnih stijena imaju statistički značajno manji udjel minerala kvarca i veći udjel minerala klorita i feldspata u odnosu na sedimentne stijene.

Background and Purpose: This paper deals with the results of the investigation of the selected heavy metal contents in forest soil in the region of an abandoned mine. The analysis of the forest ecosystem soil on the Medvednica Mountain was conducted in the region of the so-called “French Mines” (FM). The elements selected for analyses were cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) because of their toxicological characteristics. Material and Methods: In the investigated area - five entrances of the FM - composite topsoil samples (0–5 cm) were taken. Those samples were compared to the control samples which were taken outside the area affected by mines. The soil samples were analysed for the following parameters: pH, particle size distribution, organic C content and pseudo-total mass fractions of the selected heavy metals. The heavy metals were determined by atomic emission spectrometry with inductively coupled plasma (ICP-MS). Results and Conclusion: The results reveal that the soil is locally polluted, i.e. the highest mass fraction values of these four heavy metals were found in the area of the FM. Average pseudo-total fraction of Cd in the analysed topsoil samples was in the range of 0.17–4.41 mg·kg−1 (median: 0.97 mg·kg−1). Cu was found in the range of 4.54–1260 mg·kg−1 (median: 45.7 mg·kg−1). In the case of Zn, mass fraction values were found in the range of 36.8–865 mg·kg−1 (median: 137 mg·kg−1). Finally, average values of the pseudo-total fraction of Pb were found in the range of 58.4–12000 mg·kg−1 (median: 238 mg·kg−1). The results reveal that mining activities leave consequences on soil for a long time.

The determination of the mass concentration values of selected trace and major elements in bottled drinking water has been done. The bottled waters of various brands – mineral still waters as well as sparkling waters – labelled with the Made in Croatia were selected for this study. The products were collected in numerous supermarkets in Zagreb, Republic of Croatia. Drinking water stored both in PET and glass bottles were included in the research. The list of the elements that were analyzed in the bottle water samples is the following: Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Sr, and Zn. The selected metals and metalloids were quantified by direct ICP-AES measurements. The obtained results are compared to the maximum allowable concentration values of these metals and metalloids in drinking waters prescribed by the WHO and by the Croatian directives as well as to the scientific literature data. The results obtained in this study reveal that, in terms of the analyzed elements content, all Croatian bottled waters are safe for use as drinking water, especially within their expiration dates before which the analyses were conducted.

An assessment of mobility and bioavailability of trace elements present in the soil requires the determination of these elements in soil samples by an appropriate methodology. In such a context, the use of mild extraction reagents — such as water— is considered to be appropriate. On the other hand, performing an analysis of a reference material together with real samples is recommended in order to control the quality of analytical procedure. The quantification of 27 analytes in aqueous extracts of the soil CRMs samples is described. The methodology consisted of single-step extraction of analytes by deionized water (m/v = 1/10) with their subsequent direct determination by inductively coupled plasma– atomic emission spectrometry (ICPOES). Three certified reference materials (CRM) for soils have been selected as model samples: NCS DC 77302 (alias GBW 07410), Metranal-31, and Metranal-33. Although the recoveries of the selected elements obtained by water extractions are very low (i.e., the values usually do not exceed 1%), the results obtained in this study reveal the elements that by means of ICP-OES can be quantified in the water extracts of unpolluted soils are as follows: Al, Ba, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, S, Sr, Ti, and V. However, ICP-OES is not sensitive enough to quantify the elements As, Be, Cd, Co, Pb, Sb, Se, Tl, and Zn that are present in the water extracts of clean soil samples in too low mass fractions. The results obtained in this paper are useful for future uses of the three tested CRMs, in the cases of the extraction of the analytes by deionized water at room temperature.

This paper presents the results of the preliminary testing of the selected trace elements in the soils of several parks in the city of Zagreb, Republic of Croatia. In each park, the samples were taken from several points-at various distances from the roads. The samples were taken at two different depths: 0-5 and 30-45 cm. Composite samples were done for each sampling point. Microwave-assisted wet digestion of the soil samples was performed and the determination by ICP-AES technique was done. Results obtained for Al, As, Ba, Mn, Ti, V, and K are in a good agreement with the results published in the scientific literature so far. The mass fraction values of Cd, Cr, Cu, Ni, Pb, and Zn are somewhat higher than the maximum values given in the Croatian Directive on agricultural land protection against pollution. Be, Mo, Sb, Se, and Tl in the samples were present in the concentrations that are lower than their method detection limit values.

A series of novel complexes, dihalo-bis(N-p-anisoyl-2-oxo-1-naphthylideneamine-O)zinc(II) (1, 2, 3) and di-μ-halo-bis[halo(N-p-anisoyl-2-oxo-1-naphthylideneamine-O)mercury(II)] (4, 5, 6), of the general formulae [ZnX2(LH)2] and [HgX2(LH)], X = Cl, Br, I, have been prepared. The crystal structure of 1 reveals the four-co-ordinated zinc center by two halogen atoms and two oxygen atoms from neutral monodentate Schiff-base ligand in the form of distorted tetrahedron. Mercury atom in the asymmetric unit of mercury adduct 6 is co-ordinated with two iodine atoms and one oxygen atom from neutral monodentate Schiff-base ligand. The HgI2(LH) moieties are linked into 1D polymeric chains via Hg⋯I contacts. The UV–Vis spectra of the adducts obtained in the ethanolic solution as well as the results of the 1H and 13C NMR measurements performed in d6-dmso indicate that adducts undergo the decomposition after dissolving.

Matični supstrat, uz klimu, reljef, organizme i vrijeme, predstavlja jedan od pet glavnih pedogenetskih čimbenika. S pedogeneskog stajališta najvažnija su svojstva matičnog supstrata: mineralni i kemijski sastav, način i intenzitet trošenja te sadržaj biogenih elemenata. Cilj ovog rada je utvrditi utjecaj različitih matičnih supstrata na fizičke i mineralne značajke tla. Na području PP Medvednice na šest različitih litoloških cjelina otvoreno je 80 pedoloških profila: metamorfne stijene – dominantno škriljevci, metamorfne stijene – dominantno filiti, magmatske stijene, pješčenjaci, lapori i lako trošivi vapnenci. Uzorci tla uzeti su po horizontima, a analizirani su oni iz humusnoakumulatinog (A-horizont) i B-horizonta. Određeni su sljedeći parametri: debljina horizonata, dubina profila, udjel skeleta, garnulometrijski sastav tla, postojanost strukturnih mikroagregata i mineralni sastav tla (XRD) metodom rendgenske difrakcije. Rezultati istraživanja pokazuju da postoje statistički značajne razlike između različitih litoloških cjelina za sve promatrane varijable osim debljine horizonata. Najveće dubine tla su povrh laporovitih stijena, a najmanje na dolomitiziranim vapnencima, što je ponajprije uvjetovano načinom trošenja matičnog supstrata. Na svim istraživanim litološkim cjelinama, tla na području PP Medvednice vrlo su postojanih mikroagregata. U odnosu na B-horizont u humusnoakumulativnom horizontu utvrđena je veća postojanost strukturnih mikroagregata. Tla povrh lakotrošivih vapnenaca imaju statistički veći udjel gline i manji udjel krupnog i sitnog pijeska od tla ostalih litoloških cjelina. Za sve litološke cjeline teksturna oznaka najčešće je u rasponu od praškaste do glinaste ilovače, dok je na litološkoj cjelini povrh vapnenaca udjel gline statistički značajno veći, pa je teksturna oznaka u rasponu od praškaste glinuše do glinuše. Litološke cjeline povrh magmatskih i metamorfnih stijena imaju statistički značajno manji udjel minerala kvarca i veći udjel minerala klorita i feldspata u odnosu na sedimentne stijene., The highly complex lithological structure as well as topographic characteristics of the Medvednica area are responsible for its profound vegetational, micro-climatic and pedophysiographic diversity. In view of the quality of the original soil-forming material, the first place is taken by rocks and their detritus which directly govern soil physical composition. The best indicators of soil physical composition are its depth, colour, skeletal nature, particle size distribution, soil density, density of soil solid phase, total porosity, water capacity, air capacity, structure and hydraulic properties. On Medvednica, these vary greatly and play the main role in defining soil quality. The success of ecosystem management depends on the knowledge of the above factors. The goal of this research is to determine how the lithological base, or parent material, primarily affects physical (horizon thickness, profile depth, skelet proportion, soil texture, soil structure) and mineral soil properties.A total of 80 pedological profiles were opened in the Medvednica Nature Park area and evenly distributed so as to comprise all the representative lithological units. Samples of physically altered soils were taken from genetic horizons, as well as a fragment of rock, i.e. parent material, for the purpose of determining the lithological rock affiliation. Soil samples has been analayzed in the humus-accumulative (A horizon) and first under mineral horizon (mostly B horizon). The differences between the topsoil humus-accumulative and B horizon were statistically analyzed per lithological units. The samples were prepared (ISO 11464 2006) and analyzed in the laboratories of the Faculty of Forestry of the University of Zagreb and at the Croatian Geological Institute in Zagreb. According to FAO (2006), the following was determined in situ: the proportion of skelet per genetic horizon, horizon thicknesses and total profile depth. Laboratory analyses of the samples taken from genetic horizons included the particle size distribution according to ISO 11277:2009, stability of structural microaggregates according to Pernar et al. (2013) and mineral soil composition (XRD) using the X-ray diffraction method on X-ray diffractrometer X’Pert PRO MPD.For the needs of statistical analysis, parent material was divided into six characteristic units, leaning in part on the classification of Halamić et al. (2001) used during geochemical research of stream sediments on Medvednica. The lithological unit LIT1 is represented by metamorphic rocks, predominantly greenschists, muscovite chlorite and quartz-muscovite schists. The lithological unit LIT2 is represented by metamorphic rocks, predominantly phyllites. The lithological unit LIT3 consists of igneous rocks, predominantly diabases and spilites. The lithological unit LIT4 are Mesozoic clastic rocks of Lower Cretaceous age, and comprise sandstones, siltites and shales. The lithological unit LIT5 consists of Mesozoic and Tertiary clastic rocks dominantly represented by marls. LIT6 is made up of Tertiary carbonate rocks represented by lithotamnic limestones together with clay limestones (Figure 1).Statistical analysis was performed with Statistica 7 software. Descriptive statistics was made for all the analyzed variables, including the number of samples, arithmetic means and standard deviation. Differences between the analyzed variables by lithological units were tested with a one-way analysis of variance (ANOVA), on condition that the assumption of homogeneity of variance was satisfied. For those variables in which the test of homogeneity of variance was not satisfied, the Kruskal-Wallis non-parametric test was used. Type I error (a) of 5 % was considered statistically significant.The following soil types were identified in the opened pedological profiles: dystric cambisol, eutric cambisol, calcaric cambisol, stagnosol, regosol and luvisol (the percentage ratio by representation is 62 % – 19 % – 10 % – 4 % – 3 % – 2 %).Based on the comparison of soils formed in six different lithological units, it can be concluded that physical and mineral soil properties depending on type of litological units. Silty to clay loam is the most represented textural class in Medvednica Nature Park. It was found on metamorphic rocks above greenschist and phyllite, igneous rocks, sandstones and marls, whereas on easily weathered limestones the textural class ranges from silty clay to clay. The analysis of particle size distribution (content of individual fractions) showed that the profiles developed on silicate lithological parent material have on average higher sand content compared to the profiles developed on carbonate rocks, which is conditioned by the manner of parent rock weathering. Higher clay content above easily weathered limestones eventually led to variability of the textural class in relation to other lithological units. In all the investigated lithological units in terms of structural microaggregate stability, the soils in Medvednica Nature Park manifest highly stable microaggregates. In relation to the B-horizon, the humus-accumulative horizon revealed higher stability of structural microaggregates, which can be attributed to higher content of organic matter in the topsoil horizon. The soils above igneous and metamorphic rocks have significantly lower content of the mineral quartz and higher content of the minerals chlorite and feldspar in relation to the soil above sedimentary rocks. There was no difference in muscovite/illite contents in lithological substrates. Soil was the deepest above marl rocks and the shallowest above dolomitised limestones, which is primarily conditioned by the manner of parent material weathering.Our research highlights all the complexity and heterogeneity of the geological-lithological structure of Medvednica. In combination with other pedogenetic factors, it manifests even higher soil heterogeneity, which eventually causes problems in the processing and interpretation of the results.This research provides reference data on physical and mineral properties of soils in Medvednica Nature Park in the most represented lithological units. However, these data should be taken with caution and should be compared with the results of other similar studies, since the same lithological parent material may give rise to the formation of soils of different taxonomic affiliation, depending on the changes in the constellation of other pedogenetic factors (climate, vegetation, relief).

One-step microwave-assisted digestion procedures were investigated with the scope to obtain fast method for multi-elemental analysis of stream sediment samples by sector field inductively coupled plasma-mass spectrometry (SF-ICP-MS). As a model, certified reference material stream sediment (NCS DC 73309), produced by China National Analysis Center for Iron and Steel was used. The reagents whose extraction abilities have been examined were: HNO3, mixture HNO3/HCl (9:1 v/v), mixture HCl/HNO3 (3:1 v/v i.e., aqua regia), and mixture HNO3/HCl/HF (8:1:1 v/v/v). The list of the selected elements is: Ag, Al, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, K, Li, Mn, Mo, Na, Ni, Pb, Sb, Sn, Sr, Ti, Tl, V, and Zn. Most of them could be analyzed when only HNO3 for digestion was employed. For the determination of Sb, the use of aqua regia for digestion of stream sediment samples is required. Be, K, Na, Ti, and Tl can be easily and satisfactorily made available for environmental screening when digestion was performed using aqua regia, although the recoveries for these elements were better when the mixture HNO3/HCl/HF (v/v/v 8:1:1) was applied. A aplicação de procedimentos de digestão por micro-ondas em uma única etapa foi investigada visando obter um método rápido para a análise multielementar em amostras de sedimentos de córrego empregando a espectrometria de massas por plasma indutivamente acoplado (SF-ICP-MS). O material de referência certificado de sedimento de córrego produzido pelo Centro Nacional de Análise para Ferro e Aço, China (NCS CD 73309), foi selecionado como referência. Os reagentes empregados e avaliados para os procedimentos de digestão e extração foram: HNO3, mistura de HNO3/HCl (9:1 v/v), mistura de HCl/HNO3 (água régia, 3:1 v/v) e mistura de HNO3/HCl/HF (8:1:1 v/v/v). Ag, Al, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, K, Li, Mn, Mo, Na, Ni, Pb, Sb, Sn, Sr, Ti, Tl, V e Zn foram avaliados, sendo que a maioria puderam ser determinados quando somente HNO3 foi empregado para a digestão da amostra de sedimento de córrego. Para a determinação de Sb, o uso da água régia foi necessário. Berílio, K, Na, Ti e Tl foram fácil e satisfatoriamente isolados das matrizes ambientais quando água régia foi empregada para a digestão da amostra, embora os valores de recuperação para esses elementos tenham sido melhores quando a mistura HNO3/HCl/HF (8:1:1 v/v/v) foi empregada.

Methods for multi-elemental quantitative analysis of soil samples by high-resolution inductively-coupled plasma-mass spectrometry (HR–ICP–MS) with preceding one-step wet digestion in a high-pressure microwave system have been developed. The application of aqua regia as a reagent for wet digestion using a high-pressure microwave digestion system, followed by determination using HR–ICP–MS, allows an accurate, simultaneous determination of a large number of heavy metals and metalloids that are considered as potentially hazardous for the environment and health. The values of the concentrations of the elements in the analysed certified reference material (CRM) that have been obtained in this study can be used as indicative values where this CRM is used as a control for the quality of the measurements.

This study provides the preliminary data set for total dissolved trace metal concentrations in the surface water of the Sava River in Croatia and the assessment of Sava River water quality status. The highest levels of total dissolved metals were observed for Fe, Mn, and Zn (12.6 +/- 7.8 mirog L(-1), 3.44 +/- 3.95 mirog L(-1), and 2.27 +/- 1.53 mirog L(-1), respectively), the intermediate concentrations for Ni, Cu, and Cr (0.59 +/- 0.14 mirog L(-1), 0.54 +/- 0.14 mirog L(-1), and 0.32 +/- 0.06 mirog L(-1), respectively), and the lowest levels for Co, Pb, and Cd (0.064 +/- 0.022 mirog L(-1), 0.055 +/- 0.051 mirog L(-1), and 0.011 +/- 0.004 mirog L(-1), respectively). The results refer to the grab water samples taken at five sites in the period from March to June, 2006. For four trace metals (Mn, Pb, Zn, and Fe), the high temporal variability within one season was observed. It can present a problem for reliable evaluation of total dissolved concentrations of these metals in the river water, if the assessment is based on the occasional grab water sampling. The comparison of results obtained in this study with previously reported data for several unpolluted rivers indicated that Sava River water reflects a certain anthropogenic impact. However, according to the levels proposed by European regulations, it still can be classified as water containing total dissolved trace metals in concentrations not significantly above the natural level.

As a model for determination of the role of integrins in drug resistance, we used alpha(v)beta(3) integrin-negative human laryngeal carcinoma cell line (HEp2) and three HEp2-derived cell clones with a gradual increase of alpha(v)beta(3) integrin expression. The alpha(v)beta(3) integrin expression protects cells from cisplatin, mitomycin C, and doxorubicin. In HEp2-alpha(v)beta(3) integrin-expressing cells, the constitutive expression of Bcl-2 protein and the level of glutathione (GSH) were increased compared with HEp2 cells. Pretreatment of HEp2-alpha(v)beta(3) integrin-expressing cells with an inhibitor of GSH synthesis, buthionine sulfoximine (BSO), decreased the level of GSH and partially reverted drug resistance to all above-mentioned drugs, but it did not influence the expression of Bcl-2. Sensitivity to selected anticancer drugs did not change with overexpression of Bcl-2 in HEp2 cells, nor with silencing of Bcl-2 in HEp2-alpha(v)beta(3) integrin-expressing cells, indicating that Bcl-2 is not involved in resistance mechanism. There was no difference in DNA platination between HEp2 and HEp2-alpha(v)beta(3) integrin-expressing cells, indicating that the mechanism of drug resistance is independent of cisplatin detoxification by GSH. A strong increase of reactive oxidative species (ROS) formation during cisplatin or doxorubicin treatment in HEp2 cells was reduced in HEp2-alpha(v)beta(3) integrin-expressing cells. Since this increased elimination of ROS could be reverted by GSH depletion, we concluded that multidrug resistance is the consequence of GSH-dependent increased ability of alpha(v)beta(3)-expressing cells to eliminate drug-induced ROS.

DGT devices (diffusive gradients in thin films) were introduced as a new tool for the assessment of the labile metal concentrations in the surface water of Sava River in Croatia. DGT deployments were carried out at five locations, and lasted for 13-36 days. Performance evaluation in two seasons (autumn 2005 and spring 2006) revealed that reliable measurements can be achieved in the autumn period even after long-term DGT deployments, while in the spring period reproducibility was seriously affected by resin contamination with algae and particles. In the autumn period, the highest DGT-labile concentrations were measured for Fe, Mn and Zn (13.7 25.4  g L-1, 8.24 10.6  g L-1, and 1.86 0.85  g L-1, respectively), the intermediate for Ni and Cu (0.232 0.021  g L-1 and 0.166 0.062  g L-1, respectively), and the lowest for Cr, Co, Pb and Cd (0.033 0.018  g L-1, 0.022 0.009  g L-1, 0.020 0.008  g L-1 and 0.0016 0.0009  g L-1, respectively). Increased concentrations of several metals, namely Co, Cr, Mn and Fe, were found at the location downstream of the municipal sewage outlet, pointing out to detrimental effect of the point source of pollution on surface water quality. Nevertheless, DGT-labile metal concentrations in the selected section of Sava River were mostly comparable with the concentrations previously reported for unpolluted rivers.

A new analytical procedure for determination of lanthanides in environmental samples after chemical separation from major matrix elements on DOWEX 50W-X8 resin followed by preconcentration with chelating agent ammonium pyrrolidine dithiocarbamate (APDC) and analyses of thin targets by energy dispersive X-ray fluorescence (EDXRF) method using 109Cd as the source of excitation was presented. Characteristic Lalpha X-ray lines of the lanthanides were used for calculations of the net peak area and mass concentrations. The influence of pH value of the solution and addition of organic matter on the complexation was investigated. Percentage of recovery of each lanthanide after separation on DOWEX 50W-X8 resin was also determined. Accuracy of the method was tested on standard reference materials and real environmental samples (red mud material). For that purpose samples of standard reference materials and red mud were prepared as thick targets and directly analyzed (without the separation step) by EDXRF method using 241Am as the excitation source. In that case lanthanides concentrations were determined over their characteristic Kalpha X-ray lines and results were compared with those obtained after separation/preconcentration step described above. Results showed that selected lanthanides made stable complexes with APDC in the alkaline medium with the maximum recovery at pH=8. The presence of organic matter slightly modified the complexation by means of somewhat higher recovery percentage at pH lower than 7 and approx. 20% lower recovery at pH higher than 7. Recovery of the elements after separation on DOWEX 50W-X8 resin and preconcentration with APDC at pH=8 varied from 91.4% (Pr) to only 24.9% in the case of Dy. Concentrations of lanthanides measured in standard reference material and environmental samples of red mud after microwave digestion, separation on DOWEX 50W-X8 resin, preconcentration with APDC at pH=8 and recalculation on the percentage of recovery were in good agreement with certified values in the case of SRM as well as with the concentrations obtained by direct determination over Kalpha lines using 241Am excitation source in the case of red mud leading to the conclusion that presented method was applicable for the determination of lanthanides in real environmental samples.

Three Schiff-bases of the Ar—CH—N—Ar type were synthesized from 2-hydroxy-1-naphthaldehyde and o- (1), m- (2), and p-nitroaniline (3) in order to investigate the shift of the keto-amine/enol-imine tautomeric equilibrium that arises by the introduction of the electron-withdrawal nitro group. The compounds have been investigated experimentally, in the solid state and in the solution, by IR, NMR, UV spectroscopy, and X-ray single crystal analysis, and theoretically by using density functional theory (DFT). The tautomeric equilibrium is strongly shifted towards the keto-amine form despite of the nitro group position at N-phenyl ring in the solid state of molecular structures of 1, 2, and 3 (especially indicated by C—O and C—N bond distances). The keto-amine tautomeric form of the compounds is characterized by a strong, resonance assisted hydrogen bond (RAHB) of the N—H⋯ O type (the N⋅ ⋅ ⋅ O distances are 2.530(8), 2.554(2) and 2.555(5) A in 1, 2, and 3, respectively). The molecules are assembled in the crystalline state into a 3D HB network (1), centrosymmetrical dimers (2) or infinite chains (3) by the C—H⋯ O intermolecular hydrogen bonds. In contrast, UV/VIS spectra of the chloroform solution of the title compounds reveal predominance of the enol-imine form. The molecular geometries and relative stabilities of the compounds determined by using DFT find good agreement with the experimental data.

A series of novel complexes, dihalo-bis(N-benzyl-2-oxo-1-naphthylideneamine-O)zinc(II), ZnX2(bznapH)2 (1–3), dihalo-bis(N-p-tolyl-2-oxo-1-naphthylideneamine-O)zinc(II), ZnX2(tolnapH)2 (4–6), of the general formula [ZnX2(LH)2] X=Cl, Br, I, have been prepared. The crystal structures of four compounds (1–4) reveal four coordinated zinc centres by two halogen and two oxygen atoms from the Schiff-base in the form of distorted tetrahedra. Complex 4 crystallizes as the one-to-one solvate with ethanol. The tetrahedral distortion is most pronounced in the structure of ZnI2(bznapH)2 complex. X-ray structural data showed that the Schiff-base ligand in the naphthylideneamine tautomeric form is weakly bound to Zn atom in 1–4 (being in the range from 1.952(3) A in 2 to 2.002(3) A in 4). The molecular structures of 1–4 are governed by the type of halide and the corresponding Schiff-base. Although the structure comparison of ZnX2(bznapH)2 vs. ZnX2(tolnapH)2 leads to the conclusion that ligand spatial accomodation (non-planar bznapH with aliphatic interruption vs. aromatic tolnapH) is the dominating factor in the crystal structures. The crystal structures of 2–4 are dominated by van der Waals forces. There is a weak intermolecular hydrogen bond of the C–H⋯Cl type in 1 (3.710(5) A joining molecules into endless chains. The UV–Vis and 1H NMR spectra, obtained in ethanolic and acetone solution indicate that the complexes do not exist in the solutions.

Odabrane zemnoalkalijske i alkalijske kovine Ca, Mg, K i Na sastavni su dio stijena litosfere i spadaju u 8 najzastupljenijih elemenata Zemljine kore. Trošenjem stijena na površini Zemljine kore u procesima pedogeneze postaju sastavnim djelom tla. S gledišta biljne ishrane, ovi se elementi ubrajaju u biljna hraniva i to K, Ca i Mg u makroelemente, odnosno potrebne (esencijalne) elemente, a Na u korisne (beneficijalne) elemente.Cilj ovog istraživanja je utvrditi kako litološka podloga, odnosno matični supstrat na području PP Medvednica utječe na udjel Ca, Mg, K i Na u tlu, te je li njihova prostorna raspodjela osim litološkom podlogom uvjetovana i reljefom.U šumi na području PP Medvednica uzet je 181 kompozitni uzorak po pravilnoj mreži 1 × 1 km u površinskom sloju tla do 5 cm dubine. Otvoreno je 28 pedoloških profila ravnomjerno raspoređenih, tako da obuhvate sve litološke cjeline. Na uzorcima površinskog sloja tla izmjereni su pH vrijednost tla (HRN ISO 10390:2005) i udjel elemenata Ca, Mg, K, Na nakon ekstrakcije zlatotopkom (HRN ISO 11466:2004). Na uzorcima uzetim iz genetskih horizonata u pedološkim profilima određeni su granulometrijski sastav tla (HRN ISO 11277:2004), pH vrijednost tla (HRN ISO 10390:2005), udjel organskog ugljika i ukupnog dušika suhim spaljivanjem (HRN ISO 10694:2004; HRN ISO 13878:2004), mineralni sastav tla (XRD) metodom rendgenske difrakcije i udjel elemenata Ca, Mg, K, Na nakon ekstrakcije zlatotopkom (HRN ISO 11466:2004).Za potrebe statističke analize matični supstrat podijeljen je u sedam karakterističnih litoloških cjelina, koje u svom radu prilikom geokemijskih istraživanja potočnih sedimenata Medvednice koriste geolozi Halamić et al. (2001). Litološku cjelinu LIT1 čine parametamorfitne stijene, litološku cjelinu LIT2 ortometamorfitne stijene, litološku cjelinu LIT3 magmatske stijene, litološku cjelinu LIT 4 mezozojske klastične stijene, litološku cjelinu LIT5 tercijarne klastične stijene, litološku cjelinu LIT6 mezozojske karbonatne stijene i litološku cjelinu LIT7 tercijarne karbonatne stijene.Statistička analiza napravljena je u programskom paketu Statistica 7. Za sve analizirane varijable napravljena je deskriptivna statistika: broj uzoraka, minimum, donji kvartil, medijan, gornji kvartil, maksimum, aritmetička sredina, standardna devijacija, koeficijent varijance, standardna pogreška aritmetičke sredine i asimetričnost.Kako bi se isključio utjecaj outlier-a i ekstremnih vrijednosti kao srednja vrijednost uzet je medijan, a međusobne razlike između analiziranih varijabli po litološkim podlogama testirane su Kruskal-Wallisov-im neparametrijskim testom. Greška tipa I (a) od 5% smatrana je statistički značajnom.Najviša pH vrijednost zabilježena je za površinski sloj tla na litološkim podlogama LIT6 i LIT7. LIT6 ima statistički značajno višu pH vrijednost od LIT1, LIT2, LIT3, LIT4 i LIT5, a LIT7 od LIT2, LIT4 i LIT5. Za sve litološke podloge utvrđena je statistički značajna pozitivna korelacija između pH vrijednosti i koncentracije Ca. Utvrđena je i statistički značajna pozitivna korelacija između pH vrijednosti i Mg za LIT1 i LIT5, te pH vrijednosti i K za LIT2 i LIT4. S obzirom na koncentraciju Mg jasno su se izdvojile dvije grupe koje čine LIT4, LIT5 i LIT7 s nižom koncentracijom i LIT2, LIT3 i LIT6 s višom koncentracijom dok je LIT1 između navedenih grupa. S obzirom na koncentraciju K jasno su se izdvojile dvije grupe koje se statistički značajno razlikuju i to LIT2, LIT3 i LIT5 s nižom koncentracijom te LIT4, LIT6 i LIT7 s višom koncentracijom, dok je LIT1 između navedenih grupa.Na otvorenim pedološkim profilima utvrđeni su sljedeći tipovi tala: distrični kambisol, eutrični kambisol, kalkokambisol, pseudoglej obronačni, koluvij i luvisol (udjel po zastupljenosti iznosi 50% – 18% – 14% – 11% – 4% –4%). Općenito se može reći da je humusnoakumulativni horizont na Medvednici plitak – medijan iznosi 3,3 cm, a aritmetička sredina 3,9 cm. Sljedeći, najčešće kambični, horizont je debljine 31 cm, odnosno 33 cm. Raspon udjela org. C u humusnoakumulativnom horizontu kreće se od osrednje humoznog do vrlo jako humoznog tla. Po udjelu ukupnog dušika tlo je dobro do vrlo bogato opskrbljeno, a C/N odnos je povoljan. Prema granulometrijskom sastavu tlo je najčešće praškasto-ilovaste teksture, a na karbonatnoj podlozi nešto teže praškasto-glinovitoilovaste teksture. Udjel pojedinih minerala, te Ca, Mg, K i Na u humusnoakumulativnom i mineralnom horizontu je podjednak, a korelacije između horizonata su statistički značajne (p, Alkali earth metals and alkali metals Ca, Mg, K and Na are a constituent part of the lithosphere rocks and belong among the 8 most abudant elements in the Earth´s crust. They are the results of the weathering of rocks on the surface of the Earth´s crust in the process of pedogenesis. From the aspect of plant nutrition, these elements belong to plant nutrients: K, Ca and Mg belong to macro-elements or essential elements, while Na belongs to beneficial elements.The goal of this research is to establish how the lithological bedrock, or parent material in the area of Medvednica Nature Park affects the Ca, Mg, K and Na content in the soil, and whether their spatial distribution is conditioned by the relief as well as by the lithological bedrock.A total of 181 composite samples were taken in the Medvednica NP forests. Topsoil samples to a 5 cm depth were taken in a regular 1 x 1 km grid. Twenty-eight pedological profiles were opened and evenly distributed to encompass all lithological units. Soil pH values (HRN ISO 10390:2005) were measured in topsoil samples and so was the content of the elements Ca, Mg, K, and Na after extraction with aqua regia (HRN ISO 11466:2004). Determination of particle size distribution in mineral soil material (HRN ISO 11277:2004), determination of soil pH ( HRN ISO 10390:2005), determination of organic carbon and total nitrogen after dry combustion (HRN ISO 10694:2004; HRN ISO 13878:2004), mineral content of the soil (XRD) by X-ray diffraction method and content of the elements Ca, Mg, K and Na after extraction with aqua regia (HRN ISO 11466:2004) were determined in the samples taken from genetic horizons in the pedological profiles.For statistical purposes, the lithological bedrock was divided into seven characteristic lithological units, which were used by geologists Halamić et al. (2001) in their study of stream sediments on Medvednica. Lithological unit LIT1 is made up of parametamorphic rocks, Lithological unit LIT2 is composed of orthometamorphic rocks, Lithological unit LIT3 consists of igneous rocks, Lithological unit LIT4 is formed of Mesozoic clastic rocks, Lithological unit LIT5 is comprised of Tertiary clastic rocks, Lithological unit LIT6 consists of Mesozoic carbonate rocks and Lithological unit LIT7 is made up of Tertiary carbonate rocks.Statistical analysis was performed in Statistica 7 software package. Descriptive statistics was made for all the analyzed variables: number of samples, minimum, lower quartile, median, upper quartile, maximum, mean, standard deviation, coefficient of variation, standard error of mean and skewness. In order to eliminate the effect of outliers and extreme values, the median was taken as the mean value. Mutual differences between the analyzed values per lithological bedrock were tested using the Kruskal-Wallis non-parametric test. Type 1 (a) error of 5% was considered statistically significant.The highest pH value was recorded for the topsoil layer in LIT6 and LIT7. LIT6 has statistically significantly higher pH value than LIT1, LIT2, LIT3, LIT4 and LIT5, while LIT7 has statistically significantly higher pH value than LIT2, LIT4 and LIT5. Statistically significant positive correlation between pH values and Ca concentrations were found in all lithological units. Statistically significant positive correlation between pH values and Mg was also established for LIT1 and LIT5, and between pH values and K for LIT2 and LIT4. In terms of Mg concentration, two groups were clearly identified: one consisting of LIT4, LIT5 and LIT7 with lower concentration, and the other comprising LIT2, LIT3 and LIT6 with higher concentration, while LIT1 is between the two groups.The following soil types were determined in the opened pedological profiles: dystric cambisol, eutric cambisol, calcocambisol, pseudogley on slope, colluvium and luvisol (50% – 18% – 14% – 11% – 4% – 4%). In general, the humus-accumulative horizon on Mt Medvednica is shallow – the median is 3.3 cm, and the mean is 3.9 cm. The next horizon, which is usually cambic, is 31 cm and 33 dm thick. The range of organic C content in the humus accumulative horizon ranges from medium humic to very humic soil. The soil is rich to very rich in total nitrogen, and the C/N ratio is favourable. The soil texture is most frequently silty loam, while on the carbonate bedrock it is of somewhat heavier – silty clay loam. The content of individual minerals, and of Ca, Mg, K and Na in the humus-accumulative and mineral horizon is more or less equal, while the correlation between the horizons is statistically significant (p

A series of adducts of the type HgX2(C18H15NO) [X=Cl−, Br−, I−; C18H15NO=N-benzyl-2-oxo-1-naphthylideneamine (bznapH), N-p-tolyl-2-oxo-1-naphthylideneamine (tolnapH)] was obtained by refluxing the solution of the corresponding mercury(II) salt and the related naphthylideneamine in absolute ethanol in a 1:1 molar ratio. The adducts di-μ-chloro-bis[chloro(N-benzyl-2-oxo-1-naphthylideneamine)mercury(II)], HgCl2(bznapH) (1) and di-μ-bromo-bis[bromo(N-benzyl-2-oxo-1-naphthylideneamine)mercury(II)], HgBr2(bznapH) (2) are isostructural with the effective coordination of mercury being 2+2. The HgX2 moieties are retained in the adducts and contain two covalently linked chlorine [2.321(3) and 2.299(3) A in 1] or bromine atoms [2.446(1) and 2.422(1) A in 2]. These moieties are linked mutually by additional contacts of bridging halogen atoms [Hg⋯μX 3.189(2) and 3.298(1) A in 1 and 2, respectively], forming non-planar dimeric Hg2X4 units. Each Schiff-base ligand has a strong contact with mercury through the oxygen atom [Hg⋯O 2.392(5) and 2.410(5) A in 1 and 2, respectively]. The Schiff-base ligand in 1 and 2 exists as the ketoamino (quinoid) tautomeric structure with an intramolecular hydrogen bond of the NH⋯O type [2.58(1) and 2.59(1) A in 1 and 2, respectively]. On the contrary, in DMSO solution, due to dissociation of adducts 1–6, the enolimino (benzenoid) tautomeric form of the Schiff bases was established by NMR spectroscopy.

The N,N′-bis(1-naphthaldimine)-o-phenylenediamine chloroform (1/1) solvate was prepared from 2-hydroxy-1-naphthaldehyde and 1,2-phenylenediamine in a 2:1 molar ratio and characterized in solution and in the solid state using X-ray single crystal diffractometry, IR and NMR spectroscopy. The structure consists of three structural fragments: two planar, but not coplanar naphthaldimine moieties linked by phenyl ring that derived from o-phenylenediamine. The naphthaldimine fragments contain, along with naphthalene rings, six-membered pseudoaromatic chelate rings, formed by O H⋯N or N H⋯O intramolecular hydrogen bonds that retain planarity of the aldimine fragments. This structure is the first example of the coexistence of two different hydrogen bond types within Schiff base molecule, i.e. the one naphthaldimine part exists in the enolimino form (O H⋯N hydrogen bond of 2.5487(17) A), while the other exists in the ketoamino form (N H⋯O hydrogen bond of 2.5706(19) A). The different hydrogen bond types are related to the different π-electron density distribution within two parts. The amino hydrogen atom forms three-center intramolecular hydrogen bond, which includes the N H⋯O hydrogen bond of 2.5706(19) A within the ketoamino part and also the N H⋯N bond of 2.7238(18) A linking two naphthaldimine fragments of the molecule. IR and 1H and 13C NMR spectral data are consistent with revealed molecular structure in the solid state.

U radu su prikazni rezultati morfloških značajki klijanaca obične smreke (Picea abies L., H. Karst.) u različitim pH otopinama. Sjeme je tretirano s 10 različitih pH otopina, u rasponu pH od 1,5 do 6,0 (povećanje svakih 0,5). Vodene otopine priređene su susljednim razrjeđivanjem ishodne, koncentrirane sumporne kiseline (H2SO4) i ultračiste vode (, The paper presents the results of morphological properties of Norway spruce (Picea abies L., H. Karst.) seedlings in various pH solutions. The seed was treated with 10 different pH solutions with pH ranging from 1.5 to 6.0 (increase at every 0.5). Water solutions were prepared by sequential dilution of the original concentrated sumporic acid (H2SO4) and the ultrapure water (

U radu su prikazni rezultati morfloških značajki klijanaca obične smreke (Picea abies L., H. Karst.) u različitim pH otopinama. Sjeme je tretirano s 10 različitih pH otopina, u rasponu pH od 1, 5 do 6, 0 (povećanje svakih 0, 5). Vodene otopine priređene su susljednim razrjeđivanjem ishodne, koncentrirane sumporne kiseline (H2SO4) i ultračiste vode (

Summary The present study investigated the effects of salinity on the perennial species Centaurea ragusina L. interesting as a potential cash crop plant. Plants grown in culture conditions were subjected to increasing salt (0–600 mM NaCl) or mannitol (300 mM) treatments for two weeks. Effects of isoosmotic concentrations of NaCl (150 mM) and mannitol were compared and discussed in order to discriminate possible differences in C. ragusina response to ionic (NaCl) and osmotic (mannitol) components of salinity. C. ragusina plants used Na and to a lesser extent Cl ions as a primary osmotica though with higher salinity, proline accumulation increased as well. Concurrently, with increasing salinity significant reductions in plant K, Mg and Ca concentrations occurred. In addition, lower salt concentrations induced leaf succulence and increased leaf relative water content (RWC). A threshold salinity above which C.ragusina L. showed signs of damage and growth inhibition was reached at 300 mM. Activities of superoxide dismutase, catalase and ascorbate peroxidase in salinized plants seem to play an essential protective role in the scavenging processes. Regardless of the high induction of antioxidative system and massive proline accumulation, mannitol caused decrease of RWC and oxidative damage to proteins and lipids. Considering the abundance of some photosynthetic proteins (Rubisco, D1, LHCI, LHII and FNR) and PSII efficiency, it can be concluded that both salt and mannitol impaired photosynthesis in C. ragusina though salt to a much lesser extent. The results suggest that the major reason for the particular threshold of salinity tolerance in C. ragusina can be attributed to limited dilution capacity of succulent tissue. The tolerance strategies of C. ragusina to moderate salinity seem to include osmotic adjustment achieved through salt ions uptake as a dominant strategy but also highly inducible antioxidative defense.

Depending on their oxidation states, heavy metals can be highly reactive and consequently toxic to most organisms. The present study aimed to study the biological effects induced by accumulation of zinc, an essential micronutrient and aluminium, a nonessential element, in duckweed (Lemna minor L.). Relative growth rate of plants exposed to zinc (Zn) or aluminium (Al) sulfate (0.15 and 0.3 mM) for 15 days was more affected under zinc toxicity. High accumulation of both Al (maximum 2500 µ g g-1 dw) and Zn (maximum 5000 µ g g-1 dw) was accompanied by increase in dry weight under higher metal treatments. An antioxidant response was observed under both metal stresses with a large increase in superoxide dismutase and peroxidases. Contrary to that, catalase activity markedly declined in duckweed as a result of Zn treatment. Accordingly, lipid peroxidation, proline and ascorbate levels exhibited highest values in plants exposed to Zn while carotenoids level significantly decreased. These parameters were unaffected under Al stress, but H2O2 content displayed high values as under zinc stress. The results suggest induction of oxidative stress under both aluminium and zinc toxicity but also duckweeds capability to increase antioxidative defense. Additionally, Zn was found to be more toxic to duckweed than Al with concentrations applied. Due to high accumulation potential as well as tolerance through increased antioxidant capacity, duckweeds could be used for phytoremediation of moderately-level zinc and aluminum polluted waterbodies.

Single-step microwave digestion methods using four different acidic dissolving reagents were investigated with the main objective to obtain a simple, rapid method for multi-elemental analysis of marine sediment samples by high resolution inductively coupled plasma-mass spectrometry (HRICP-MS), especially for environmental studies. Closed-vessels microwave digestion procedures were carried out using the reagents as follows: HNO3, mixture of HNO3-HCl (φ r = 9: 1), aqua regia, and mixture of HNO3-HCl-HF (φ r = 8: 1: 1). The elements analyzed were: Al, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, K, Li, Mn, Mo, Na, Ni, Pb, Sb, Sn, Sr, Ti, Tl, V, and Zn. Good recoveries were established for many of the metals analyzed even when only nitric acid was employed. However, for a good recovery of Sb and Tl, aqua regia should be employed.

Thallium (Tl) is a heavy metal included in priority pollutant list due to its high toxicity. In this study, we assess toxicity of monovalent thallium, which is highly soluble and easily absorbed by water macrophytes. We exposed Lemna minor plants to Tl(I)-acetate, the effect of which was monitored after 1-, 4-, 7- and 14-d exposure. After 14-d exposure, 0.2, 0.5, 1.0 and 2.0 μ M Tl-acetate reduced the frond-number growth rate by 21.1%, 39.4%, 66% and 83.1%, respectively. In order to rule out possible effects of the acetate group, plants were also exposed to potassium(I)-acetate. An ICP-MS analysis showed that the Tl content in plant tissue after 7-d exposure followed the Tl-acetate concentration in tested solutions. Tl-acetate induced a modulation of the antioxidative response by depleting the ascorbate content and affecting the activities of antioxidative enzymes. Superoxide dismutase showed a continuous increase of activity after Tl exposure. Unlike superoxide dismutase, other antioxidative enzymes displayed a biphasic response to both the concentration and the period of the exposure. During 7-d exposure, a decreased catalase activity in plants exposed to 1.0 and/or 2.0 μ M Tl-acetate was observed. In contrast, 14-d exposure increased the catalase activity already at the concentration of 0.2 μ M. Exposure of up to 7 d increased the ascorbate peroxidase activity except in plants exposed to 2.0 μ M Tl-acetate, while 14-d exposure decreased the ascorbate peroxidase activity already at the concentration of 0.5 μ M. The pyrogallol peroxidase activity rised after 1- and 4-d exposure to Tl-acetate. Longer exposure (7 and 14 d) decreased the pyrogallol peroxidase activity in plants exposed to the highest two concentrations. In general, short-term exposure to Tl-acetate activated the antioxidant protective mechanisms, resulting in a development of adaptive mechanisms to highly toxic Tl. The adaptation was confirmed by a growth analysis, which showed a recovery of the frond-number growth rates in Tl-treated plants after the initial toxic phase. In spite of the activation of the antioxidative response, higher concentrations of Tl-acetate induced a hydrogen peroxide accumulation as well as an oxidative damage to lipids, proteins and DNA. Long-term exposure to Tl-acetate induced an impairment of some components of the antioxidative defense and a severe oxidative damage to biomolecules. The genotoxic effect was evaluated by an alkaline version of Comet assay. Results of the cellular and acellular Comet assays revealed an indirect genotoxic effect of Tl-acetate, suggesting an oxidatively induced damage to DNA.

Although duckweed Lemna minor L. is a known accumulator of cadmium, detailed studies on its physiological and/or defense responses to this metal are still lacking. In this study, the effects of 10 µ ; M CdCl2 on Lemna minor were monitored after 6 and 12 days of treatment, while growth was estimated every two days. Cadmium treatment resulted in progressive accumulation of the metal in the plants and led to a decrease in the growth rate to 54% of the control value. The metal also considerably impaired chloroplast ultrastructure and caused a significant reduction in pigment content, i.e., at day 12, by 30% and 34% for chlorophylls a and b, and by 25% for carotenoids. During cadmium treatment, the contents of malondialdehyde (MDA) and endogenous H2O2 progressively increased (rising 77% and 46% above the controls by day 12), indicating that cadmium induced considerable oxidative stress. On the other hand, higher activities of pyrogallol peroxidase (PPX), ascorbate peroxidase (APX) and catalase (CAT), as well as the induction of a new APX isoform, in cadmium-treated plants, clearly showed activation of an antioxidative response. At day 6, only PPX activity was significantly above the controls (15%), while, at day 12, PPX, APX and CAT activities were increased (74%, 78% and 63%). Cadmium also led to accumulation of the heat shock protein 70 (HSP70) and induced an additional isoform of this protein. The obtained results suggest that cadmium (10 μ M) is phytotoxic to Lemna minor, inducing oxidative stress, and that antioxidative enzymes and HSP70 play important roles in the defense against cadmium toxicity.

Mercury is one of the most toxic and hazardous pollutant which occurs in the environment in different chemical forms, of which methylmercury is the most dangerous. Recently it was recognised that long-term anthropogenic inputs of mercury into environment resulted in the global mercury pollution and it was concluded that action should be taken to quantify the pollution sources and reduce human-generated releases of mercury. This paper presents new data on mercury levels in aquatic sediments from about 15 Croatian rivers, lakes and estuaries. It also brings data on mercury concentrations in soils from eight different regions of Croatia. Distribution of mercury species is discussed in more details for the Sava River, the Krka estuary and the Kastela Bay on the eastern Adriatic coast. Results show that sediments and soils from Croatia are generally not contaminated by mercury, except for some rivers and coastal locations under direct anthropogenic influence.

In the crystal structure of the title compound, [Zn(C 18 H 14 -NO 2 ) 2 ].C 2 H 6 O, the Zn atom displays a highly distorted octahedral coordination involving the O and N atoms of two molecules of the Schiff base 1-[N-(2-methoxyphenyl)imino-methyl]naphthalen-2(1H)-one, which acts as an O,N,O'-tridentate ligand. The ethanol molecule is bound to the methoxy group of one ligand molecule via a hydrogen bond.

Two structural isomers of 5-methoxysalicylaldimine Schiff-bases; N-(o-hydroxyphenyl)-5-methoxysalicylaldimine, [(Sal-o-OH-ph)H], and N-(m-hydroxyphenyl)-5-methoxysalicylaldimine, [(Sal-m-OH-ph)H], have been prepared and characterized in the solid state by means of the single crystal X-ray diffractometry at 298 and 200 K, and also by IR spectroscopy. Two structures, which are different only in the position of the N-substituent phenyl ring hydroxy group, are characterized by different tautomeric forms, i.e. ortho- and meta-hydroxy derivatives exist as the N–H⋯O and O–H⋯N tautomers, respectively. The tautomeric forms are influenced by the different intermolecular hydrogen bonding patterns of the molecules in the crystalline state. The stabilization of the non-favourable NH form of (Sal-o-OH-ph)H is ascribed to stronger intermolecular O–H⋯O hydrogen bonds in (Sal-o-OH-ph)H than in (Sal-m-OH-ph)H. Both compounds form discrete centrosymmetrical dimers leading to 14- and 16-membered rings for (Sal-o-OH-ph)H and (Sal-m-OH-ph)H, respectively. The molecules are non-planar and twisted around C–N single bond by 13.9(2) and 10.5(2)° in (Sal-o-OH-ph)H and (Sal-m-OH-ph)H, respectively. The crystal structure analyses at 200 K show that there is no change in the type of the tautomeric form in comparison to 298 K data.

Thallium (Tl) is a metal of great toxicological concern because it is highly toxic to all living organisms through mechanisms that are yet poorly understood. Since Tl is accumulated by important crops, the present study aimed to analyze the biological effects induced by bioaccumulation of Tl in broad bean (Vicia faba L.) as well as the plant's antioxidative defense mechanisms usually activated by heavy metals. Thallium toxicity was related to production of reactive oxygen species in leaves and roots of broad bean seedlings following short-term (72 h) exposure to thallium (I) acetate (0, 0.5, 1, 5, and 10 mg/L) by evaluating DNA damage and oxidative stress parameters as well as antioxidative response. The possible antagonistic effect of potassium (K) was tested by combined treatment with 5 mg/L of Tl (Tl+) and 10 mg/L of potassium (K+) acetate. Accumulation of Tl+ in roots was 50 to 250 times higher than in broad bean shoots and was accompanied by increase in dry weight and proline. Despite responsive antioxidative defense (increased activities of superoxide dismutase, ascorbate peroxidase, and pyrogallol peroxidase), Tl+ caused oxidative damage to lipids and proteins as evaluated by malondialdehyde and carbonyl group levels, and induced DNA strand breaks. Combined treatment caused no oxidative alternations to lipids and proteins though it induced DNA damage. The difference in Tl-induced genotoxicity following both acellular and cellular exposure implies indirect DNA damage. Results obtained indicate that oxidative stress is involved in the mechanism of Tl toxicity and that the tolerance of broad bean to Tl is achieved, at least in part, through the increased activity of antioxidant enzymes.