TY - JOUR AU - Abrankó, László AU - Kmellar, B AU - Fodor, Péter TI - Comparison of extraction procedures for methylmercury determination by a SPME-GC-AFS system JF - MICROCHEMICAL JOURNAL J2 - MICROCHEM J VL - 85 PY - 2007 IS - 1 SP - 122 EP - 126 PG - 5 SN - 0026-265X DO - 10.1016/j.microc.2006.04.001 UR - https://m2.mtmt.hu/api/publication/1390067 ID - 1390067 AB - In this study the comparison of three different alkaline extraction techniques carried out with methanolic NaOH followed by phenylation derivatization for the determination of methylmercury in marine fish was performed. The investigated three methods differed in the technique how the extraction assisting energy was introduced to the sample. Namely, closed vessel ultrasonic bath, an open vessel technique using an ultrasonic probe and the microwave assisted extraction procedures were characterized and optimized. Optimum values of 3 h at 75 degrees C for the ultrasonic bath, 25 min for the ultrasonic probe and 6 min at 60 W for the microwave method were obtained. All three methods were validated using the BCR-464 tuna fish certified reference material. (c) 2006 Elsevier B.V. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Kapolna, E AU - Gergely, V AU - Dernovics, Mihály AU - Illes, A AU - Fodor, Péter TI - Fate of selenium species in sesame seeds during simulated bakery process JF - JOURNAL OF FOOD ENGINEERING J2 - J FOOD ENG VL - 79 PY - 2007 IS - 2 SP - 494 EP - 501 PG - 8 SN - 0260-8774 DO - 10.1016/j.jfoodeng.2006.01.075 UR - https://m2.mtmt.hu/api/publication/1148355 ID - 1148355 N1 - KW: Bakery process KW: HPLC-UV-HG-AFS KW: Rancidity KW: Selenium speciation KW: Selenomethionine KW: Sesame seed Cited By (since 1996): 3 AB - Hulled sesame seeds possessing relatively low selenium content were investigated for Se-speciation in order to assess the possible role of sesame seeds in Se-supplementation. As sesame seed is widely used by sprinkling over bakery products in Hungary, this study also deals with the effect of a simulated bakery process on selenium species distribution. Since fatty seeds, like sesame tend to become rancid in consequence of no appropriate or long storage time, the prospect of conversion of selenium species was under investigation. The sample was analysed for total selenium and selenium speciation by the means of a coupled technique, HPLC-UV-HG-AFS. Peculiar attention was paid to avoid the misidentification of selenium species when co-elution problems may occur by applying independent HPLC separation techniques (cation and anion-exchange chromatographies). For validating the total Se measurements, a certified reference material (BCR-422) was used. Different sample preparation techniques were applied to reach the maximal extraction efficiency. An adequate extraction efficiency (83%) was achieved, making the quantification of selenomethionine (552 ? 14 ?g SeMet as Se kg-1 in the original sesame) possible. Neither the simulated bakery process (roasting) nor forced oxidation caused any changes in the Se-species distribution of sesame seeds. ? 2006 Elsevier Ltd. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Jókainé Szatura, Zsuzsa AU - Abrankó, László AU - Fodor, Péter TI - SPME-GC-pyrolysis-AFS determination of methylmercury in marine fish products by alkaline sample preparation and aqueous phase phenylation derivatization JF - JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY J2 - J AGR FOOD CHEM VL - 53 PY - 2005 IS - 14 SP - 5499 EP - 5505 PG - 7 SN - 0021-8561 DO - 10.1021/jf0501140 UR - https://m2.mtmt.hu/api/publication/1390070 ID - 1390070 AB - Characterization of a cost-efficient analytical method based on alkaline sample digestion with KOH and NaOH, followed by aqueous phase phenylation derivatization with NaBPh4 and solid phase microextraction (SPME) for the determination of methylmercury in typical fish-containing food samples commercially available in Hungary, is reported. The sample preparation procedure along with the applied SPME-GC-pyrolysis-AFS system was validated by measuring certified reference materials (CRM) BCR-464, TORT-2, and a candidate CRM BCR 710. To carry out an estimation of average Hungarian methylmercury exposures via marine fish and/or fish-containing food consumption, 16 commercially available products and 3 pooled representative seafood samples of-according to a previous European survey-the three most consumed fish species in Hungary, herring, sardines, and hake, were analyzed. Methylmercury concentrations of the analyzed samples were in the range 0.016-0.137 mu g of MeHg g(-1) dry weight as Hg. LA - English DB - MTMT ER - TY - JOUR AU - Schaeffer, R AU - Marczika Andrásné Sörös, Csilla AU - Ipolyi, I AU - Fodor, Péter AU - Thomaidis, N S TI - Determination of arsenic species in seafood samples from the Aegean Sea by liquid chromatography-(photo-oxidation)-hydride generation-atomic fluorescence spectrometry JF - ANALYTICA CHIMICA ACTA J2 - ANAL CHIM ACTA VL - 547 PY - 2005 IS - 1 SP - 109 EP - 118 PG - 10 SN - 0003-2670 DO - 10.1016/j.aca.2005.01.032 UR - https://m2.mtmt.hu/api/publication/1721069 ID - 1721069 N1 - Megjegyzés-22035656 Chemicals/CAS: arsenic trioxide, 1303-24-8, 1327-53-3, 13464-58-9, 15502-74-6; arsenic, 7440-38-2; arsenobetaine, 64436-13-1; arsenocholine, 39895-81-3 Department of Applied Chemistry, Corvinus University, Villanyi ut 29-35, 1118 Budapest, Hungary Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Panepistiomopolis, Zografou, 15776 Athens, Greece Cited By :55 Export Date: 31 May 2021 CODEN: ACACA Correspondence Address: Thomaidis, N.S.; Laboratory of Analytical Chemistry, Panepistiomopolis, Zografou, 15776 Athens, Greece; email: ntho@chem.uoa.gr LA - English DB - MTMT ER - TY - JOUR AU - Bodo, E T AU - Stefánka, Zsolt AU - Ipolyi, I AU - Marczika Andrásné Sörös, Csilla AU - Dernovics, Mihály AU - Fodor, Péter TI - Preparation, homogeneity and stability studies of a candidate LRM for Se speciation JF - ANALYTICAL AND BIOANALYTICAL CHEMISTRY J2 - ANAL BIOANAL CHEM VL - 377 PY - 2003 IS - 1 SP - 32 EP - 38 PG - 7 SN - 1618-2642 DO - 10.1007/s00216-003-1941-y UR - https://m2.mtmt.hu/api/publication/1148346 ID - 1148346 AB - A laboratory reference material (LRM) was prepared from Brazil nuts (Bertholletia excelsa) for quality control (QC) purposes of selenium speciation. The preparation of this LRM led through the usual operation steps applied during routine reference material production from biota samples-preparation of the raw material, homogenisation, storage design, checking of homogeneity, microbiological status and possible irradiation effects, and monitoring the species stability vs time at different storage temperatures. The selenium speciation studies to check species stability were carried out on a HPLC-UV-HG-AFS measurement set-up. Special attention was paid to the correct identification of selenium species by applying independent HPLC separation techniques (ion-pairing and anion-exchange chromatography). The concentration of selenomethionine (SeMet) and total Se content were quantified (79.9 ?g g-1 (calculated as Se) and 82.9 ?g g-1, respectively). The homogeneity and stability of this candidate reference material passed the relevant tests recommended by Bureau Communautaire de Re?fe?rence (BCR). ? Springer-Verlag 2003. LA - English DB - MTMT ER - TY - JOUR AU - Ipolyi, I AU - Corns, W AU - Stockwell, P AU - Fodor, Péter TI - Speciation of inorganic selenium and selenoamino acids by an HPLC-UV-HG-AFS system JF - JOURNAL OF AUTOMATED METHODS & MANAGEMENT IN CHEMISTRY J2 - J AUTOM METHOD MANAG VL - 23 PY - 2001 SP - 167 EP - 172 PG - 6 SN - 1463-9246 UR - https://m2.mtmt.hu/api/publication/1719773 ID - 1719773 LA - English DB - MTMT ER - TY - JOUR AU - Ipolyi, I AU - Stefánka, Zsolt AU - Fodor, Péter TI - Speciation of Se(IV) and the selenoamino acids by high-performance liquid chromatography-direct hydride generation-atomic fluorescence spectrometry JF - ANALYTICA CHIMICA ACTA J2 - ANAL CHIM ACTA VL - 435 PY - 2001 IS - 2 SP - 367 EP - 375 PG - 9 SN - 0003-2670 DO - 10.1016/S0003-2670(01)00868-6 UR - https://m2.mtmt.hu/api/publication/1466228 ID - 1466228 AB - The speciation of selenocystine (SeCys), selenomethionine (SeMet), selenoethionine (SeEt) and Se(IV) was performed by on-line coupling of high-performance liquid chromatography (HPLC) and atomic fluorescence spectrometry (AFS) with hydride generation (HG) as high efficiency sample introduction system. Reversed-phase liquid chromatography was applied to separate the selenium species with 0.01M ammonium acetate buffer (pH=4) eluent containing 0.5% (v/v) methanol and 0.1moll-1 of DDAB. The operating conditions for chromatographic separation (gradient elution, run time) and hydride generation (concentration of HCl and NaBH4 solution, argon and hydrogen flow rates) were carefully optimized. The efficiency of hydride generation for all of the four species was measured. Detection limits (DLs) obtained for SeCys, SeMet, SeEt and Se(IV) are 18, 70, 96, and 16μgl-1, respectively. The analytical performance of the method was controlled by measuring the selenium content of spiked selenium food supplements. The range of obtained recoveries is 90-110%. © 2001 Elsevier Science B.V. LA - English DB - MTMT ER - TY - JOUR AU - Stefánka, Zsolt AU - Ipolyi, I AU - Dernovics, Mihály AU - Fodor, Péter TI - Comparison of sample preparation methods based on proteolytic enzymatic processes for Se-speciation of edible mushroom (Agaricus bisporus) samples JF - TALANTA J2 - TALANTA VL - 55 PY - 2001 IS - 3 SP - 437 EP - 447 PG - 11 SN - 0039-9140 DO - 10.1016/S0039-9140(01)00398-8 UR - https://m2.mtmt.hu/api/publication/1148344 ID - 1148344 AB - A sequential sample preparation process was developed for the speciation analysis for Se-enriched edible mushroom, Agaricus bisporus containing 110.2 ?g of total Se/g sample. Five different sample extraction methods were compared and the most efficient method (a three-step process involving the use of water extraction and two proteolytic enzymes - pepsin and trypsin) proved to be the most suitable for extracting selenium, with an extraction efficiency of 75%. As the analogues of these enzymes play an important role in human digestion the bioavailability of the selenium present in the sample was estimated. Selenocystine (SeCys2) and Se(IV) were detected in considerable amounts (27.7 ?g Se/g sample and 46.4 ?g Se/g sample, respectively). For the quality control of peak identification a spiking procedure was developed, using a low selenium mushroom containing 4.3 ?g of total Se/g sample. During the analysis with HPLC-HHPN (Hydraulic High Pressure Nebuliser)-AFS complicated background effects and matrix problems were observed: stable and reproducible signals generated by the low selenium mushroom and the compounds used in sample preparation were detected. The three-step sample preparation method connected with the HPLC-HHPN-AFS system proved to be applicable for the speciation analysis of the Se-enriched Agaricus bisporus. ? 2001 Elsevier Science B.V. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Slejkovec, Z AU - Salma, Imre AU - van Elteren, JT AU - Zemplen-Papp, E TI - Speciation of arsenic in coarse and fine urban aerosols using sequential extraction combined with liquid chromatography and atomic fluorescence detection JF - FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY J2 - FRESENIUS J ANAL CHEM VL - 366 PY - 2000 IS - 8 SP - 830 EP - 834 PG - 5 SN - 0937-0633 DO - 10.1007/s002160051580 UR - https://m2.mtmt.hu/api/publication/1489454 ID - 1489454 N1 - Megjegyzés-21643539 [3096] LA - English DB - MTMT ER - TY - JOUR AU - Mester, Zoltán AU - Fodor, Péter TI - Selenium speciation with on-column preconcentration high-performance liquid chromatography - atomic fluorescence spectrometry using ultrasonic nebulization technique JF - ANALYTICA CHIMICA ACTA J2 - ANAL CHIM ACTA VL - 386 PY - 1999 IS - 1-2 SP - 89 EP - 97 PG - 9 SN - 0003-2670 DO - 10.1016/S0003-2670(99)00010-0 UR - https://m2.mtmt.hu/api/publication/1719683 ID - 1719683 AB - A system has been developed to determine two inorganic selenium species Se(IV) and Se(VI). In this novel technique liquid chromatography (LC) is coupled to an atomic fluorescence spectrometer (AFS) using an ultrasonic nebulizer (USN) as interface. The effect of hydrogen and argon gas flow rates, nebulization temperature, loop volume, pump rate and phosphate buffer conditions were investigated. A simple on-column preconcentration method was worked out. The detection limit for Se(IV) and Se(VI) using this preconcentration method are 8.6 and 30ngcm-3, respectively. Copyright (C) 1999 Elsevier Science B.V. LA - English DB - MTMT ER - TY - JOUR AU - Puskel, E AU - Mester, Zoltán AU - Fodor, Péter TI - Determination of selenoamino acids by high-performance liquid chromatography-hydraulic high pressure nebulization-atomic fluorescence spectrometry JF - JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY J2 - J ANAL ATOM SPECTROM VL - 14 PY - 1999 IS - 6 SP - 973 EP - 976 PG - 4 SN - 0267-9477 DO - 10.1039/a901651a UR - https://m2.mtmt.hu/api/publication/22008536 ID - 22008536 LA - English DB - MTMT ER - TY - JOUR AU - Mester, Zoltán AU - Fodor, Péter TI - High performance liquid chromatography - hydride generation - atomic fluorescence spectroscopic determination of arsenic species in water JF - JOURNAL OF CHROMATOGRAPHY A J2 - J CHROMATOGR A VL - 756 PY - 1996 SP - 292 EP - 299 PG - 8 SN - 0021-9673 DO - 10.1016/S0021-9673(96)00625-5 UR - https://m2.mtmt.hu/api/publication/1710628 ID - 1710628 LA - English DB - MTMT ER - TY - JOUR AU - Mester, Zoltán AU - Woller, Ágnes AU - Fodor, Péter TI - Determination of Arsenic Species by High Performance Liquid Chromatography –Hydride Generation- Ultrasonic Nebulizer – AFS JF - MICROCHEMICAL JOURNAL J2 - MICROCHEM J VL - 54 PY - 1996 IS - 3 SP - 184 EP - 194 PG - 11 SN - 0026-265X DO - 10.1006/mchj.1996.0094 UR - https://m2.mtmt.hu/api/publication/1710615 ID - 1710615 AB - A technique to determine four species of arsenic (AsIII, AsV, dimethylarsinic (DMAs), and monomethylarsonic (MMAs) acids) where high-performance liquid chromatography was coupled to an atomic fluorescence spectrometer using an ultrasonic nebulizer as an interface has been further improved by the use of hydride generation. The effect of hydride conditions on signal intensities has been investigated. The detection limits for AsIII, AsV, DMAs, and MMAs were 2.5, 6, 3.2, and 2 ng, respectively (at 250 mm3 volume injected). The linearity for all four arsenic species were in the range 25-1000 ng. © 1996 Academic Press, Inc. LA - English DB - MTMT ER - TY - JOUR AU - SZAKACS, O AU - LASZTITY, A AU - Horváth, Zalán TI - BREAKDOWN OF ORGANIC MERCURY-COMPOUNDS BY HYDROCHLORIC ACID-PERMANGANATE OR BROMINE MONOCHLORIDE SOLUTION FOR THE DETERMINATION OF MERCURY BY COLD-VAPOR ATOMIC-ABSORPTION SPECTROMETRY JF - ANALYTICA CHIMICA ACTA J2 - ANAL CHIM ACTA VL - 121 PY - 1980 IS - DEC SP - 219 EP - 224 PG - 6 SN - 0003-2670 DO - 10.1016/S0003-2670(01)84416-0 UR - https://m2.mtmt.hu/api/publication/2897834 ID - 2897834 N1 - Cited By :37 Export Date: 21 November 2023 CODEN: ACACA Correspondence Address: Szakács, O.; Institute of Inorganic and Analytical Chemistry, L.Eötvös University, PO Box 123, 1443 BudapestHungary, Hungary LA - English DB - MTMT ER -