TY  - JOUR
AU  - Abrankó, László
AU  - Jókainé Szatura, Zsuzsa
AU  - Fodor, Péter
TI  - Investigation of the species-specific degradation behaviour of methylmercury and ethylmercury under microwave irradiation
JF  - ANALYTICAL AND BIOANALYTICAL CHEMISTRY
J2  - ANAL BIOANAL CHEM
VL  - 383
PY  - 2005
IS  - 3
SP  - 448
EP  - 453
PG  - 6
SN  - 1618-2642
DO  - 10.1007/s00216-005-3395-x
UR  - https://m2.mtmt.hu/api/publication/1390068
ID  - 1390068
AB  - The degradation behaviour of methylmercury (MeHg) under microwave irradiation is investigated, as is the (different) degradation behaviour of ethylmercury (EtHg) under similar irradiation. A simple and highly sensitive SPME-GC-pyrolysis-AFS system was used to analyse the aqueous MeHg and EtHg standard solutions after derivatization with sodium tetraphenylborate (NaBPh4). Samples were irradiated in a microwave digester at microwave powers ranging from 20 to 160 W for durations of 2 to 10 min. The different tolerances towards microwave treatment of the two organomercury species were evident. Practically no degradation was experienced for MeHg for up to 8 minutes of irradiation at 120 W or for up to 4 minutes at 160 W. Significant analyte loss was observed for EtHg after 2 minutes at 40 W of microwave power.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Yang, L
AU  - Sturgeon, R E
AU  - McSheehy, S
AU  - Mester, Zoltán
TI  - Comparison of extraction methods for quantitation of methionine and selenomethionine in yeast by species specific isotope dilution gas chromatography-mass spectrometry
JF  - JOURNAL OF CHROMATOGRAPHY A
J2  - J CHROMATOGR A
VL  - 1055
PY  - 2004
IS  - 1-2
SP  - 177
EP  - 184
PG  - 8
SN  - 0021-9673
DO  - 10.1016/j.chroma.2004.09.018
UR  - https://m2.mtmt.hu/api/publication/21785825
ID  - 21785825
N1  - Chemicals/CAS: cyanogen bromide, 506-68-3; mesylic acid, 2386-57-4, 75-75-2; methionine, 59-51-8, 63-68-3, 7005-18-7; pronase, 9036-06-0; proteinase, 9001-92-7; selenomethionine, 1464-42-2, 3211-76-5; triacylglycerol lipase, 9001-62-1; Isotopes; Methionine, 63-68-3; Selenomethionine, 1464-42-2
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  -