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 - Grinberg, P. AU - Campos, R.C. AU - Mester, Zoltán AU - Sturgeon, R.E. TI - A comparison of alkyl derivatization methods for speciation of mercury based on solid phase microextraction gas chromatography with furnace atomization plasma emission spectrometry detection JF - JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY J2 - J ANAL ATOM SPECTROM VL - 18 PY - 2003 IS - 8 SP - 902 EP - 909 PG - 8 SN - 0267-9477 DO - 10.1039/b212545e UR - https://m2.mtmt.hu/api/publication/30393739 ID - 30393739 N1 - Institute for National Measurements Standards, National Research Council of Canada, Ottawa, Ont. K1A 0R6, Canada Department of Chemistry, Pontificia Universidade Católica do Rio de Janeiro, Rua Marques de Sao Vicente, 225, 22453-900 Rio de Janeiro-RJ, Brazil Cited By :50 Export Date: 15 January 2019 Correspondence Address: Sturgeon, R.E.; Institute for National Measurements Standards, National Research Council of Canada, Ottawa, Ont. K1A 0R6, Canada; email: ralph.sturgeon@nrc.ca AB - Several derivatizing agents were evaluated for use in speciating mercury in biological samples using solid phase microextraction in conjunction with tandem gas chromatography-furnace atomization plasma emission spectrometry (SPME-GC-FAPES). Following digestion with methanolic potassium hydroxide, the pH of the samples was adjusted and NaCl added when necessary. The mercury species were then derivatized with sodium tetraphenylborate or sodium tetrapropylbqrate and extracted by SPME using a 100 um PDMS coated fiber. The derivatized species were then separated by GC and detected by FAPES. All experimental parameters were optimized for best separation and analytical response. Propylation proved to be more sensitive, robust and faster than ethylation or phenylation, leading to procedural detection limits of 0.55 ng g-1 for methylmercury, 0.34 ng g-1 for ethylmercury and 0.23 ng g-1 for inorganic mercury. An intra-day and intra-fiber precision of typically 2.2% was achieved whereas long-term (4 months) and inter-fiber reproducibility precision was typically 4.4%. The accuracy of the method was validated by the analysis of Certified Reference Materials (DORM-2, DOLT-2 and TORT-2) from the National Research Council of Canada. © The Royal Society of Chemistry 2003. LA - English DB - MTMT ER - TY - JOUR AU - Grinberg, P. AU - Campos, R.C. AU - Mester, Zoltán AU - Sturgeon, R.E. TI - Solid phase microextraction capillary gas chromatography combined with furnace atomization plasma emission spectrometry for speciation of mercury in fish tissues JF - SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY J2 - SPECTROCHIM ACTA B VL - 58 PY - 2003 IS - 3 SP - 427 EP - 441 PG - 15 SN - 0584-8547 DO - 10.1016/S0584-8547(02)00272-0 UR - https://m2.mtmt.hu/api/publication/30393749 ID - 30393749 AB - The use of solid phase microextraction in conjunction with tandem gas chromatography-furnace atomization plasma emission spectrometry (SPME-GC-FAPES) was evaluated for the determination of methylmercury and inorganic mercury in fish tissue. Samples were digested with methanolic potassium hydroxide, derivatized with sodium tetraethylborate and extracted by SPME. After the SPME extraction, species were separated by GC and detected by FAPES. All experimental parameters were optimized for best separation and analytical response. A repeatability precision of typically 2% can be achieved with long-term (3 months) reproducibility precision of 4.3%. Certified Reference Materials DORM-2, DOLT-2 and TORT-2 from the National Research Council of Canada were analyzed to verify the accuracy of this technique. Detection limits of 1.5 ng g-1 for methylmercury and 0.7 ng g-1 for inorganic mercury in biological tissues were obtained. © 2002 Elsevier Science B.V. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Yang, L. AU - Colombini, V. AU - Maxwell, P. AU - Mester, Zoltán AU - Sturgeon, R.E. TI - Application of isotope dilution to the determination of methylmercury in fish tissue by solid-phase microextraction gas chromatography-mass spectrometry JF - JOURNAL OF CHROMATOGRAPHY A J2 - J CHROMATOGR A VL - 1011 PY - 2003 IS - 1-2 SP - 135 EP - 142 PG - 8 SN - 0021-9673 DO - 10.1016/S0021-9673(03)01122-1 UR - https://m2.mtmt.hu/api/publication/30393744 ID - 30393744 N1 - Cited By :55 Export Date: 15 January 2019 CODEN: JCRAE Correspondence Address: Yang, L.; Inst. for Natl. Msmt. Standards, National Research Council Canada, Ottawa, Ont. K1A 0R6, Canada; email: lu.yang@nrc.ca Chemicals/CAS: methylmercury, 16056-34-1, 593-74-8; potassium hydroxide, 1310-58-3 AB - Species-specific isotope dilution (ID) calibration using solid-phase microextraction (SPME) in combination with gas chromatography-mass spectrometry (GC-MS) for separation and detection of methylmercury (MeHg) in fish tissue is described. Samples were digested with methanolic potassium hydroxide. Analytes were propylated and headspace sampled with a polydimethylsiloxane-coated SPME fused-silica fiber. ID analysis was performed using a laboratory-synthesized 198Hg-enriched methylmercury (Me198Hg) spike. Using selective ion monitoring (SIM) mode, the intensities of Me 202HgPr+ at m/z 260 and Me198HgPr+ at m/z 256 were used to calculate the m/z ratio at 260/256, which was used to quantify MeHg in NRCC CRM DORM-2 fish tissue. A MeHg concentration of 4.336±0.091 μg g-1 (one standard deviation, n=4) as Hg was obtained in DORM-2, in good agreement with the certified value of 4.47±0.32 μg g-1 (95% confidence interval). A concentration of 4.58±0.31 μg g-1 was determined by standard additions calibration using ethylmercury (EtHg) as an internal standard. The three-fold improvement in the precision of measured MeHg concentrations using ID highlights its superiority in providing more precise results compared to the method of standard additions. A method detection limit (3 S.D.) of 0.037 μg g-1 was estimated based on a 0.25 g subsample of DORM-2. Crown Copyright © 2003 Published by Elsevier B.V. All rights reserved. LA - English DB - MTMT ER - TY - JOUR AU - Yang, L. AU - Mester, Zoltán AU - Sturgeon, R.E. TI - Determination of methylmercury in fish tissues by isotope dilution SPME-GC-ICP-MS JF - JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY J2 - J ANAL ATOM SPECTROM VL - 18 PY - 2003 IS - 5 SP - 431 EP - 436 PG - 6 SN - 0267-9477 DO - 10.1039/b301299a UR - https://m2.mtmt.hu/api/publication/30393740 ID - 30393740 N1 - Cited By :73 Export Date: 15 January 2019 Correspondence Address: Yang, L.; Institute for National Measurement Standards, National Research Council Canada, Ottawa, Ont. K1A 0R6, Canada; email: Lu.Yang@nrc.ca AB - A method is described for the accurate and precise determination of monomethylmercury (MMHg) by species specific isotope dilution (ID) calibration using solid phase microextraction (SPME) in combination with gas Chromatographic (GC) separation and inductively coupled plasma mass spectrometric (ICP-MS) detection. Samples were digested with methanolic potassium hydroxide, derivatized in aqueous solution with sodium tetrapropylborate and headspace sampled with a polydimethylsiloxane coated SPME fused silica fiber. The analyte was then directly transferred from the fiber to the head of the GC column for desorption by insertion of the fiber through the heated injection port. Reverse spike ID analysis was performed to determine the accurate concentration of an in-house synthesized 198Hg-enriched monomethylmercury (MM 198Hg) spike [candidate Certified Reference Material (CRM) EOM-1] using two natural abundance MMHg standards. Concentrations of 0.719 ± 0.015 and 4.484 ± 0.029 μg g-1 (one standard deviation, n = 4) as Hg were obtained for MMHg in NRCC CRMs DOLT-2 and DORM-2, respectively, using the present method. These are in good agreement with the certified values of 0.693 ± 0.053 and 4.47 ± 0.32 μg g-1 (as 95% confidence interval). A MMHg concentration of 4.69 ± 0.12 μg g -1 (one standard deviation, n = 4) as Hg in DORM-2 was subsequently determined by standard additions calibration using ethylmercury (EtHg) as an internal standard. A nearly. 4-fold improvement in the precision of determination using ID was obtained, clearly demonstrating its superiority in providing more precise results compared to the method of standard additions. The method was applied to the determination of MMHg in a new biological CRM DOLT-3 and a concentration of 1.540 ± 0.025 μg g-1 (one standard deviation, n = 6) as Hg was obtained. A method detection limit (3σ) of 2.1. ng g-1 was estimated for a 0.25 g of subsample, sufficiently low for the routine determination of MMHg in most biological samples. © The Royal Society of Chemistry 2003. 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 -