György Heltai

Moderated pressure microwave digestion system for preparation of biological samples.

A new type closed digestion vessel was constructed for digestion of biological samples. In this the vapour pressure can be maintained on moderated level (150-300 kPa) by means of an internal cooling spiral. During the operation the reflux of the condensed acid and water vapour continuously renews the liquid phase over the sample. By this way a less expensive microwave system may be applied. The performance of this instrument is practically equal to the commercial systems. The digestion time of plant and tissue samples is 5-10 min and the analytical results for reference materials are in good agreement with the reference values.

Study of application of BCR sequential extraction procedure for fractionation of heavy metal content of soils, sediments, and gravitation dusts

This article deals with the application of original and modified Community Bureau of Reference (BCR) sequential extraction scheme for fractionation of contaminant metallic elements (Zn, Cd, Pb, Ni, Cr, and Cu) in sediments, soils, and aerial gravitation dusts. Contamination level and extractability of contaminant element in our internal laboratory soil, sediment, and gravitation dust reference samples was studied by original BCR procedure proposed to certified reference material (CRM) 601 sediment reference material. A preliminary comparative study was performed to control the extraction ability of original and modified BCR procedure using CRM 601 and 701, respectively. It was established that original BCR scheme can be applied for different kinds of samples (sediment, soil, dust) when necessary sample amount is available; however, one has to calculate with analyte losses due to pH instability during the second and third leaching steps and readsorption may occur after third leaching step during the phase separation. This latter observation was verified by direct solid sample analysis of original samples and third-step solid residue.

Phytoextraction Potential of Wild Type and 35S-GSHI Transgenic Poplar Trees (Populus × Canescens) for Environmental Pollutants Herbicide Paraquat, Salt Sodium, Zinc Sulfate and Nitric Oxide In Vitro

Phytoextraction potentials of two transgenic (TR) poplar (Populus × canescens) clones TRggs11 and TRlgl6 were compared with that of wild-type (WT) following exposure to paraquat, zinc sulfate, common salt and nitric oxide (NO), using a leaf-disc system incubated for 21 days on EDTA-containing nutritive WPM media in vitro. Glutathione (GSH) contents of leaf discs of TRlgl6 and TRggs11 showed increments to 296% and 190%, respectively, compared with WT. NO exposure led to a twofold GSH content in TRlgl6, which was coupled with a significantly increased sulfate uptake when exposed to 10−3 M ZnSO4. The highest mineral contents of Na, Zn, Mn, Cu, and Mo was observed in the TRggs11 clone. Salt-induced activity of catalase enzyme increased in both TR clones significantly compared with WT under NaCl (0.75% and 1.5%) exposure. The in silico sequence analyses of gsh1 genes revealed that P. × canadensis and Salix sachalinensis show the closest sequence similarity to that of P. × canescens, which predicted an active GSH production with high phytoextraction potentials of these species with indication for their use where P. × canescens can not be grown.

Multi-Elemental Inductively Coupled Plasma-Optical Emission Spectroscopic Calibration Problems of the Sequential Extraction Procedure for the Fractionation of the Heavy Metal Content from Aquatic Sediments

Abstract For the characterisation of the environmental mobility of heavy metal contamination in aquatic sediments, the EU Bureau of Reference has proposed a fractionation by sequential extraction procedure. For its validation, the CRM-701 sample is available containing Cd, Cr, Cu, Ni, Pb, and Zn. In this paper, the matrix-matched calibration problems are presented. A multi-elemental inductively coupled plasma-optical emission technique is employed for the detection of heavy metals in the extracts. It was established that the sensitivities are strongly influenced by the extractants, which causes significant matrix effects: the sensitivities are strongly influenced by the solvents applied in extraction steps; the summarised recoveries show an acceptable agreement with the certified values; however, in the individual extraction steps for certain elements significant differences may occur due to the neglected interferences. Therefore, further optimisation is required utilising the flexible line selection possibility offered by the HORIBA Jobin Yvon ACTIVA-M instrument.

Coupling of microwave induced plasma optical emission spectrometry with HPLC separation for speciation analysis of Cr(III)/Cr(VI)

Feasibility and limitations of direct coupling of high performance liquid chromatographic (HPLC) separation to microwave induced plasma (MIP)-optical emission spectrometry (OES) for elementspecific detection was tested and compared to inductively coupled plasma (ICP)-optical emission spectrometric detection on the basis of the Cr(III)/Cr(VI) speciation analysis of water samples. Coupling was performed by a hydraulic high pressure nebulizer (HHPN) radiative-heating/watercooling interface which provides about 20 % and 80 % aerosol yield in the case of helium and argon carrier gases, respectively. Desolvation efficiency of aqueous solutions was approximately 80 %. Applying the ion-pair HPLC separation, the organic eluents and reagents in the MIP cause a 50–75 % signal suppression for Cr(VI) and 25–50 % for Cr(III). In a pure aqueous solution the MIP Cr(VI) signal was by 20 % lower than that of Cr(III). These effects were lower using the ICP source, but they cannot be neglected. Easily ionizable matrix elements (Na, Ca) can cause 70 % signal suppression in the MIP, and 20 % in the ICP. Therefore, species dependent calibration is required in both cases. In the case of HPLC detection by MIP-OES, the detection limit was 13 ng for Cr(III), and 18 ng for Cr(VI). Using the ICP-OES detection, the detection limit was 0.2 ng for Cr (III) and 0.4 ng for Cr (VI). The linear dynamic ranges in both cases were two orders of magnitude.

Improvement of the sequential extraction procedure based on supercritical CO2 and subcritical H2O solvents for the estimation of the environmentally mobile potentially toxic element fractions of sediments and soils

The estimation of environmental risk caused by pollution with potentially toxic elements (PTE) is usually carried out using the (3+1) step sequential extraction procedure suggested in 1993 by the Community Bureau of Reference (BCR). In the 1st step the water-soluble, exchangeable and carbonate-bound element content is extracted with acetic acid. In 2002 a fractionation procedure based on the application of supercritical CO 2 , subcritical H2O and of a mixture of subcritical H 2 O/CO 2 was proposed, which allowed the water-soluble and carbonatebound element contents to be extracted separately from sediment or soil samples weighed into the preparative column of a supercritical fluid extractor and diluted with quartz sand in a mass ratio of 1:20. The aim of the present study was to develop a new reduced-size column construction with which this dilution rate could be decreased to 1:2. A kinetic study was performed to determine the extraction time necessary for samples with different carbonate contents and the extracted element contents were compared to the results of the BCR sequential procedure on the same samples. It was established that fractionation using the reduced-size column may be a rapid way to obtain more reliable information on the easily mobilizable (watersoluble and carbonate-bound) PTE content of soils and sediments than was previously available to supplement BCR fractionation.

Heavy Metal Balance in a Communal Wastewater Treatment Plant

In early 2000, two contamination events at Baia Mare first and Baia Borsa second involving large amounts of toxic elements impacted the Hungarian section of the River Tisza with disastrous ecological and economical impacts. We evaluated the sort- and long-term effects of this pollution by determining the total and bioavailable concentrations of potentially toxic metals from soil samples collected along the Tisza (Tivadar, Vasarosnameny, Rakamaz, and Tiszacsege) in 2000 and between 2011 and 2013. The current and previous results were compared in respect of copper and lead contents.

Evaluation of the Heavy Metal Content of the Upper Tisza River Floodplain Soils over the last Decade

Abstract In early 2000, two contamination events at Baia Mare first and Baia Borsa second involving large amounts of toxic elements impacted the Hungarian section of the River Tisza with disastrous ecological and economical impacts. We evaluated the sort- and long-term effects of this pollution by determining the total and bioavailable concentrations of potentially toxic metals from soil samples collected along the Tisza (Tivadar, Vásárosnamény, Rakamaz, and Tiszacsege) in 2000 and between 2011 and 2013. The current and previous results were compared in respect of copper and lead contents.