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The objective of this study was to determine the mineral content in the leaves and flowers of wild-grown Sambucus nigracollected from eleven different locations in Kosovo. The samples were digested in a microwave system using the wet digestion method. The minerals were determined by the application of inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). A total of 31 elements were determined, 15 elements by the ICP-AES method (Al, B, Ba, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, P, Sr, V, and Zn) and 16 elements by the ICP-MS method (Ag, As, Be, Bi, Cd, Co, Cs, Ga, Hg, In, Li, Ni, Pb, Rb, Tl, and U). The leaves of S. nigrashow a higher content of minerals compared to the flowers, except for the flower of the sample SN-FL10, which is characterized by a high concentration of Fe, Al, Pb, Be, and Tl. The concentration of heavy metals and toxic elements (Pb, Cd, and Hg) was within the permissible concentrations according to Eur. Ph.

A systematic study was carried out to investigate the distribution of chemical elements in the sediment and soil samples collected from Crn Drim River Basin, Republic of Macedonia. For this purpose, 18 samples of river sediment, 19 samples of lake sediment, 16 samples of surface (0–5 cm) and 16 samples of bottom (20–30 cm) soil were collected within the basin. From the sewerage systems in the towns of Resen, Ohrid, Struga and Debar, 11 samples of urban sediment were collected. The determination of the content of 22 elements was performed by using inductively coupled plasma atomic emission spectrometry. Cluster and factor analyses were applied in order to show the associations of chemical elements. According to a correlation coefficient matrix of all sediment samples, a strong correlation (over 0.70) was identified between the content of the following elements: Zn–Cu, Ni–Cr, V–Fe, Sr–Ca, Fe–Cr, P–Cu, Ni–Cu, Zn–P and V–Cr. Factor analysis of the data resulted in three factors: Factor 1 (Fe, V, Al, Mn, Li), Factor 2 (Zn, Cu, Ag, Pb) and Factor 3 (Co, Ni, Cr). The elements included in factors F2 and F3 were internally correlated and belong to one cluster. Comparative statistics with three methods [ttest, F ratio and R(T/B)] showed no difference between the distribution of various chemical elements in top (T) and bottom (B) soil samples. The results show that the samples of urban sediment have a high content of heavy metals, which represent a risk to the environment and the river basin of Crn Drim, especially for the natural Prespa and Ohrid lakes.

In the present study, we analysed spatial and temporal heterogeneity of the limnological characteristics to provide more detailed information about the processes taking place within Mantovo Reservoir (Republic of Macedonia). The relationship between principal macroinvertebrate species and environmental variables was analysed in order to explore factors that dominantly affect community distribution pattern. Unlike the most reservoirs, strong longitudinal gradient for suspended organic matter and nutrients (total phosphorous, nitrates and nitrites) along the reservoir doesn’t exist. However, the process of thermal stratification has a strong influence on the metabolism and structure of the Mantovo ecosystem, which can be demonstrated by the vertical and longitudinal distribution of dissolved oxygen (DO), CO2, pH and metals concentrations. Canonical Correspondence Analysis (CCA) indicated that the main factors controlling spatial distribution of Limnodrilus hoffmeisteri and Chironomus plumosus group were temperature, dissolved oxygen and manganese, including sulphates for C. plumous group. Chaoborus crystallinus showed opposite distribution pattern. Cladotanytarsus mancus group was strongly associated with shallower part (littoral and sublittoral) of Mantovo Reservoir characterized by favourable oxygen condition. None of the environmental variables included in CCA showed any relationship with density of Procladius sp.

AbstractThe major and trace element contents in three iron-based ore reference materials were investigated using two methods of k0-based neutron activation analysis (k0-NAA): instrumental (k0-INAA) and radiochemical (k0-RNAA). To avoid interferences from iron in the determination of elements present at trace levels, a method using radiochemical separation was applied (k0-RNAA). Determination of the investigated elements by k0-RNAA in the aqueous phase from hydrochloric acid solution was performed after extraction of iron by diisopropyl ether (DIPE). It was found that Fe elimination lowered the limit of detection for some elements, thus enabling the determination of their content. The distribution of 39 elements (with intermediate/medium and long half-life radionuclides) present in the studied materials after Fe removal was investigated.

The method for determination of major and trace elements in iron oxide [hematite (Fe2O3)] and sulfide [pyrite (FeS2) and chalcopyrite (CuFeS2)] minerals using the k0-method of neutron activation analysis in both forms: instrumental (k0-INAA) and radiochemical (k0-RNAA) was suggested. In order to avoid interferences from iron on the determination of elements present in trace levels, radiochemical separation was made. Determination of the investigated elements in the aqueous phase was performed by k0-RNAA after extraction of iron by isoamyl acetate (IAA) and diisopropyl ether (DIPE) from hydrochloric acid solution. The distribution of 35 elements in extraction systems (with intermediate/medium and long half-lived radionuclides) present in the studied minerals was investigated.

A simple, rapid and precise HPLC method has been developed for the assay of verapamil in human plasma. The clean up of the plasma samples was tested using several adsorbents for solid-phase extraction and best recovery was obtained using mixed-mode cartridges (HLB - hydrophilic-lipophilic balance) ranging between 94.70 and 103.71%. HPLC separation was performed with isocratic elution on Lichrospher 60 RP-select B column (250 mm × 4 mm I.D., 5 μm particle size). The mobile phase was 40% acetonitrile and 0.025 mol/L KH2PO4 with pH 2.5 at flow rate of 1 mL/min. Diltiazem was used as internal standard and the detection wavelength was 200 nm. The calibration curves were linear in the range of 10–500 ng/mL. The developed method is convenient for routine analysis of verapamil in human plasma.

Methods for the direct determination of Ni in human blood serum and urine by electrothermal atomic absorption spectrometry (ETAAS) are described. Hydrogen peroxide was proposed as matrix modifier, assisting thermal decomposition of proteins during the ashing step. A pyrolysis temperature of 1,200 °C was found to be optimal while 2,100 °C and 2,200 °C were found to be optimal atomizing temperatures for Ni in serum and urine respectively. Calibration was performed by using a calibration curve prepared with aqueous standard solutions of Ni (glycine must be used as modifier for Ni in aqueous solutions). The limits of detection, defined as the blank values plus 3 times the standard deviation of the blank values, were 0.2 µg/L for both serum and urine samples. Relative standard deviations for serum samples with concentrations of Ni in the range 0.5–2 µg/L were 10–15% and for urine samples with Ni concentrations in the range 0.5–2.5 µg/L were 8–10%.

A method for thallium determination in some sulfide minerals (sphalerite, galena, orpiment and realgar) by electrothermal atomic absorption spectrometry has been proposed. Mineral samples were dissolved in a mixture of HNO3and HCl. The effect of interfering elements (Zn, Pb and As) on the determination of Tl in the investigated minerals was studied. These investigations show that it is not possible to determine thallium directly from solutions obtained by dissolution of minerals in mineral acids, because these matrix elements tend to decrease the absorbance of thallium. Also, it was found that the investigated minerals contain iron that tends to increase the absorbance of thallium. Therefore, a method for extraction of thallium with isoamyl acetate from 10 mol/l HCl media was proposed. In these conditions, Zn, Pb and As remain in the inorganic phase, but iron and thallium are extracted into organic phase. Reextraction of iron from the organic layer was performed with 4 mol/l H2SO4. The determination of thallium was performed in the organic phase using Pd as modifier. The investigated sulfide minerals originated from different mines from the Republic of Macedonia. The relative standard-deviation range was between 2.20 to 3.92%. The detection limit of the method (calculated as 3SD of the blank) was found to be 0.05 µg/g.

Abstract.:  The applicability of tetramethylenedithiocarbamate (TMDTC−) and hexamethylenedithiocarbamate (HMDTC−) for colloid flotation separation of manganese in traces from fresh (spring, well and tap) water was studied. The experimental conditions for the successful manganese separation and preconcentration before electrothermal atomic absorption spectrometric (ETAAS) determination were optimised. Higher enrichment of manganese was achieved when a larger amount of HMDTC− is used. Applying iron(III) hexamethylenedithiocarbamate, Fe(HMDTC)3, as a precipitate collector, manganese was determined at μg/L levels singly or simultaneously with lead and zinc in 1 L of water sample. The applicability of the proposed procedure have been verified by analyses of fresh water samples using the method of standard addition, as well as by comparing the results obtained by ETAAS with those obtained by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The detection limit of manganese using this method is 0.025 μg/L.

Tl(I) and Tl(III) are preconcentrated simultaneously from aqueous solutions by colloid precipitate flotation using two collectors: hydrated iron(III) oxide (Fe2O3·xH2O) and iron(III) tetramethylenedithiocarbamate (Fe(TMDTC)3). After the coprecipitation step and the addition of foaming agents, Tl(I) and Tl(III) were separated from the water by a stream of air bubbles. Various factors affecting Tl(I) and Tl(III) recoveries during the separation from water, including the collector mass, the nature of the supporting electrolyte, pH, ζpotential of the collector particle surfaces, type of tenside, etc., were investigated. Within the optimal pH range (6–6.5), establishing by a recommended procedure, Tl(I) and Tl(III) were separated quantitatively (94.9–100.0%) with 30 mg Fe(III). Both Tl ions were simultaneously separated without any previous conversion of one type of Tl ion to the other. Total Tl determination was performed by electrothermal atomic absorption spectrometry by previous matrix modification of the concentrated samples. The determination limit of Tl by this method is 0.108 μg l−1.

Total chromium is removed from dilute aqueous solutions by means of hexamethyleneammonium hexamethylenedithiocarbamate (HMA-HMDTC) as a new reagent used for flotation. Amount of collector-hydrated iron(III) oxide (Fe2O3·xH2O) and iron(III) hexamethylenedithiocarbamate (Fe(HMDTC)3), pH, ionic strength, induction time, etc., necessary for the successful simultaneous incorporation of Cr(III) and Cr(VI) traces into the structure of collectors was studied. At established pH (6.0) and ionic strength (0.02 mol/L), using NaDDS as foaming reagent, total chromium can be separated quantitatively with 10 mg Fe(III) and 0.0003 mol HMDTC−added to 1 L of water sample. Electrothermal vaporization atomic absorption spectrometry (ETVAAS) was applied for determination of chromium concentration in tap and spring waters. The recoveries of total chromium from natural water samples have been higher than 95.5%. The limit of detection of chromium by this method is 0.01 μg/L.

A method for determination of thallium in sulphide geological samples by x-ray fluorescence spectrometry is presented. The samples were prepared in form of glass discs by fusion with lithium tetraborate and with potassium nitrate as an oxidizing agent. The limit of determination was 0.016% (w/w) Tl, with the possibility of decreasing it to 0.006% (w/w) Tl by using the method of addition. Elements such as Zn, Cd, Cu, Fe and Pb, present as major matrix constituents, did not influence the intensity of background radiation on the position of the Tl Lβ1 line. In this way it was possible to determine small quantities of thallium in ore samples simultaneously with other elements. The standard deviation of the determination of small contents of thallium [in the range 0.020–0.10% (w/w) was 0.0016%. The sensitivity of method was 600 counts s^-1 per 1% (w/w) Tl. © 1998 John Wiley & Sons, Ltd.

Abstract: Thallium(III) forms a ternary complex of yellow colour with iodoacetic acid and organic bases, especially hexamethylenetetramine. The complex is soluble in water and various organic solvents. Zinc, copper, cadmium and iron do not form complexes with these reagents, so that a spectrophotometric determination of thallium in zinc and its alloys is possible. The limit of detection is 15 mgrgthinspg–1, the molar absorption coefficient about 2000 mol-1thinspl-1thinspcm-1.

A flotation method is proposed for the quantitative preconcentration and determination of total chromium by electrothermal atomic absorption spectrometry in fresh water samples, without previous reduction or oxidation of the chromium ion state. Hydrated iron(III) oxide and iron(III) tetramethylenedithiocarbamate were used as precipitating collectors. The detection limit of the method is 0.01 µg/L.

Samples of Thymus alsarensisRonniger, an endemic species for the Allchar locality, were evaluated for their polyphenolic composition and heavy metals. Allchar district is an abandoned antimony-arsenic-thallium deposit in the north-west of Kožuf Mountain, R. Macedonia, with a unique mineral composition affecting the mineral composition of the flora. A systematic method for phenolic compounds characterization was developed using mass spectrometry coupled to HPLC/DAD. Analyses were focused on the polyphenolic compounds to establish a possible correlation to the region specific heavy metals As and Tl in the different organs of T. alsarensis. Twenty-seven polyphenols: phenolic acid derivatives and flavonoid glycosides of luteolin, apigenin, quercetin, and kaempferol were detected; contents were higher in the leaves and flowers compared with stems and roots. Quinic acid (1), prolithospermic acid (6), salvianolic acid B (7), salvianolic acid A (8), monomethyl lithospermate (9), luteolin dihexoside (12), luteolin pentosyl-hexoside (14), luteolin acetyl pentosyl-hexoside (16), luteolin acetyl hexoside (17), luteolin dipentoside (21), luteolin pentoside (24), luteolin acetyl dipentoside (25), kaempferol pentosyl-hexoside (19) and kaempferol acetyl pentosyl-hexoside (22) were detected in T. alsarensisfor the first time.To assay the content of As and Tl, root, stem, leaf and flower samples were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). Significant accumulation of As and Tl was observed with As content from 0.25 to 140 mg/kg and Tl from 0.10 to 496 mg/kg. The content of As was much higher in the roots, while the content of Tl was significantly higher in the roots, flowers and leaves in all T. alsarensisspecimens. Comparison of the results obtained for total polyphenols and for As and Tl content does not suggest any correlation (positive or negative) between the total phenolic content and the content of Tl and As. On the other hand, it is evident that the soil rich with specific heavy metals (Tl and As) affects the type of polyphenolic compounds produced in different organs, compared with other Thymusspecies growing on soil that is not contaminated.

Chemical characterization was made of over-ground flowering parts of Sideritis scardicafrom R. Macedonia and S. raeserifrom both R. Macedonia and R. Albania. GC/FID/MS investigation of the n-hexane extracts revealed more than 90 components, dominated by diterpenes and hydrocarbons. The most abundant components were hentriacontane, nonacosane and heptacosane, and two other components both with MW=286, probably diterpenes, which were not fully identified. In addition, the content of total phenols, made by the Folin-Cioclateu method, ranged up to 50.8 and up to 48.9 mg gallic acid/g for S. scardicaand S. raeseri, respectively. Free radical scavenging activity was evaluated by DPPH assay and the activity, presented as IC50values, ranged from 3.2-8.9 mg/mL and 7.6-12.6 mg/mL for S. scardicaand S. raeseri, respectively. The content of twenty minerals in dried over-ground parts of the plants and in water tea-infusions were determined by the ICP-AES method and some of them alternatively by ETAAS. The most abundant minerals were K > Ca > Mg > P > Fe > Al > Na. The microelements and toxic elements contents were represented in the following order: Zn > Mn > B > Ba > Cu > Sr > Li > Ni > Cr > Co, and Cd > Pb > As, respectively. Water tea-infusions contained a large portion of the total K, P, Na, Cu and Pb, but smaller amounts of the other elements.