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 - Quetel, CR AU - Snell, JP AU - Aregbe, Y AU - Abrankó, László AU - Jókainé Szatura, Zsuzsa AU - Brunori, C AU - Morabito, R AU - Hagan, W AU - Azemard, S AU - Wyse, E AU - Fajon, V AU - Horvat, M AU - Logar, M AU - Donard, OFX AU - Krupp, E AU - Entwisle, J AU - Hearn, R AU - Schantz, M AU - Inagaki, K AU - Takatsu, A AU - Grinberg, P AU - Willlie, S AU - Dimock, B AU - Hintelmann, H AU - Zhu, J AU - Gonzalez, EB AU - Centineo, G AU - Alonso, JEG AU - Sanz-Medel, A AU - Bjorn, E TI - Methylmercury in tuna: demonstrating measurement capabilities and evaluating comparability of results worldwide from the CCQM P-39 comparison JF - JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY J2 - J ANAL ATOM SPECTROM VL - 20 PY - 2005 IS - 10 SP - 1058 EP - 1066 PG - 9 SN - 0267-9477 DO - 10.1039/b505368d UR - https://m2.mtmt.hu/api/publication/1390069 ID - 1390069 AB - Six metrology institutes (NMIs) representing at the Comite 'International des Poids et Mesures (CIPM) 4 Member States of the Metre Convention and 2 international organisations, and 8 "expert'' laboratories selected outside CIPM have compared their capabilities to quantitatively measure methylmercury (MeHg) in a prepared tuna material containing approximately 4.3 mg kg(-1) Hg. This comparison was the object of the CIPM - Comite Consultatif pour la Quantite de Matiere (CCQM) Pilot Study 39, organised by the Institute for Reference Materials and Measurements (IRMM), from the European Commission - Joint Research Centre. Beside the test material itself, a bottle of the BCR-464 tuna Certified Reference Material (CRM) and an ampoule of IRMM-670, a 202 Hg isotope enriched MeHg candidate isotopic CRM, were distributed to all participants, who were free to apply the measurement strategy of their choice. Four, including 1 NMI, relied on external calibration or the method of standard additions, whereas the other 10 implemented an isotope dilution mass spectrometry (IDMS) approach and chose to use the IRMM-670 for their measurements. Alkaline digestion at room temperature ( with manual shaking) or high temperature ( under sonication, oven or hot plate conditions) was employed by most participants, with hydrochloric acid leaching the second most popular choice. Alkylation ( 4 phenylations, 4 ethylations and 3 propylations) in the aqueous phase was preferred by a large majority over butylation by the Grignard reaction. All participants were requested to estimate the uncertainty associated with their results and 9 out of 14 stated relative combined uncertainties below 6% (k = 2). Despite this apparent consensus, the perception of which factor caused the largest contribution to this estimation differed among participants because of the differences in the analytical methodologies deployed but also because of wide differences of the concepts of uncertainty estimation. The mixture mode' (MM) median, calculated also from the measurement uncertainties stated by the participants, was 1.967 +/- 0.204 x 10(-5) mol kg(-1) (95% confidence). Twelve of the results were re-grouped within a range of less than 0.3 x 10(-5) mol kg(-1) (MM median = 1.967 +/- 0.162 x 10(-5) mol kg(-1), 95% confidence): they nearly all (1 exception) overlapped with each other within k = 2 stated uncertainties. For the other 2 results the uncertainty seemed to have been particularly underestimated as they lay, respectively, at more than 20% above and less than - 40% below the overall average. The relative standard deviation of the results of 9 laboratories out of the 10 that applied IDMS was about 2.6%. It can be assumed from the degree of equivalence shown by 12 out of 14 study participants that, at present, laboratories worldwide are potentially able to supply accurate results for MeHg in fish-type matrices ( containing about 2 x 10(-5) mol kg(-1)) within +/- 10% uncertainty. This encouraging outcome permitted scheduling of a follow-up CCQM-K43 key comparison for a lower MeHg content level in salmon tissues. LA - English DB - MTMT ER - TY - JOUR AU - Mester, Zoltán AU - Lam, J. AU - Sturgeon, R. AU - Pawliszyn, J. TI - Determination of methylmercury by solid-phase microextraction inductively coupled plasma mass spectrometry: A new sample introduction method for volatile metal species JF - JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY J2 - J ANAL ATOM SPECTROM VL - 15 PY - 2000 IS - 7 SP - 837 EP - 842 PG - 6 SN - 0267-9477 DO - 10.1039/b000883o UR - https://m2.mtmt.hu/api/publication/30393759 ID - 30393759 N1 - Inst. for Natl. Msrmt. Standards, National Research Council of Canada, Ottawa, Ont. K1A 0R9, Canada Department of Chemistry, University of Waterloo, Waterloo, Ont. N2L 3GI, Canada Department of Applied Chemistry, Szent István University, Budapest, Hungary Cited By :84 Export Date: 15 January 2019 CODEN: JASPE Correspondence Address: Mester, Zoltan; Natl Research Council of Canada, Ottawa, Canada AB - Direct coupling of solid-phase microextraction (SPME) with inductively coupled plasma mass spectrometry (ICP-MS) is described for methylmercury speciation. A thermal desorption interface, consisting of a heated, glass-lined splitless-type GC injector, was placed directly at the base of the torch to minimize the length of transfer line. This arrangement provides for fast desorption and high sample introduction efficiency. Direct liquid immersion and headspace extraction of methylmercury was studied, including the effect of temperature and time on the extraction efficiency. For clean solutions, immersion sampling SPME provided good sensitivity that was linear over two orders of magnitude whereas headspace sampling showed 15% lower sensitivity, but a linear range of more than three orders of magnitude. The detection limit for headspace methylmercury sampling was 0.2 ng ml-1. Calibration by the method of additions using direct extraction revealed a severe matrix effect with biological tissue samples, diminishing the methylmercury response 70-fold, whereas that obtained by headspace extraction was statistically indistinguishable from signals generated using matrix free standards. Analytical results showed good agreement between certified and measured values for analysis of NRCC DORM-2, (Dogfish muscle) and DOLT-2 (Dogfish liver) reference materials. LA - English DB - MTMT ER -