István Virág

Leaching of antimony from polyethylene terephthalate (PET) bottles into mineral water.

The Sb leaching from polyethylene terephthalate (PET) package material into 10 different brands of still (non-carbonated) and sparkling (carbonated) Hungarian mineral water purchased in supermarkets was investigated by inductively coupled plasma sector field mass spectrometry (ICP-SF-MS). The Sb concentration measured in PET package materials varied between 210 and 290 mg/kg. Generally, the Sb concentration of still mineral water was lower than that of sparkling in the case of identical storage time. For modelling improper storage conditions, storage time (10-950 days), temperature (22 degrees C-70 degrees C), illumination (dark vs. 23 W daylight lamp for 116 h) as well as bottle volume (0.5, 1.0 and 1.5 L) were taken into consideration. Under certain extreme light and temperature storage conditions, the Sb concentration of some samples exceeded the concentration value of 2 ng/mL. The extent of Sb leaching from the PET recipients of different brands of mineral water can differ by even one order of magnitude in experiments conducted under the same conditions. Thus, the adequate selection of the polymer used for the production of the PET bottle for the solar water disinfection (SODIS) procedure seems to ensure low Sb levels in the water samples.

Influence of different bentonites on the rare earth element concentrations of clarified Romanian wines

The rare earth element (REE) concentrations of 19 Romanian young wine samples originating from the Dealurile Moldovei viticulture area were determined by double focusing inductively coupled plasma mass spectrometry (DF-ICP-MS) after microwave-assisted digestion with nitric acid. The determination of Eu was hampered by the BaO molecular interference. Generally, the red wine samples were more concentrated for REEs than the white wine samples studied. The REE concentrations of the four bentonites (Gelbenton, Evergel, BW200, Tükrös) determined after their fusion were higher by three orders of magnitude than those of the wine samples. After a simulated wine purification process performed with these bentonite samples and a red and white pool samples, the REE concentrations of the clarified wine samples increased by 1.2-1.5 times for red, and 1.3-3 times for white wines in case of the fibrous bentonite sample (Gelbenton), by about 2-5 times in case of the bentonite containing ovalbumin, caseine and gelatine (Evergel), meanwhile this factor was about 20-25 for Na bentonite powder samples (BW200, Tükrös). On basis of the chemometric evaluation using the REE concentrations as input data, the majority of the Feteasca wines belonged to the same cluster as well as the two Cabernet Sauvignon to another subcluster. The adequate choice of the bentonite may allow the use of REEs as fingerprints for determining the wine provenance.

Determination of lead isotope ratios in clinopyroxene by inductively coupled plasma mass spectrometry applying solution nebulization or laser ablation sample introduction techniques

Lead isotope ratios were determined in clinopyroxene originating from Hungary and in a Japanese basalt standard (JB-2) by a single-collector inductively coupled plasma sector field mass spectrometer applying solution nebulization and laser ablation (LA) as sample introduction techniques. The solutions were prepared by dissolution of samples in a mixture of HF/HNO3 and isolation of analyte by Pb-selective crown ether resin. The separation of Pb from the matrix and other compounds lowered the contribution of the major interference (204Hg) to the counts of 204Pb to less than 1%. More than 94.5% and 98.4% of the Pb content of the clinopyroxene and JB-2 samples, respectively, could be collected on the resin. The relative standard deviations of the measured Pb isotope ratios obtained by solution technique changed between 0.3% and 0.5%. In the case of LA with repetition rate of 10 Hz and spot size of 100 µm these values were between 1.3% and 1.6%.