Zoltán Mester - Academia.edu (original) (raw)
Papers by Zoltán Mester
A simple, rapid, and sensitive method, which allowed us to simultaneously determine seven benzodi... more A simple, rapid, and sensitive method, which allowed us to simultaneously determine seven benzodiazepines (diazepam, nordiazepam, temazepam, oxazepam, 7-aminoflunitrazepam, N-desmethylflunitrazepam, and clonazepam) in buffer solution and in urine and serum samples, was investigated by automated in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS). In-tube SPME, in which the analytes were extracted from the sample directly into
Analytical chemistry, Jan 9, 2015
A novel and sensitive approach for the accurate determination of Sb in natural waters is describe... more A novel and sensitive approach for the accurate determination of Sb in natural waters is described using photochemical vapor generation (PVG) coupled with inductively coupled plasma mass spectrometry (ICPMS) for detection. Utilizing a unique flow-through photochemical reactor capable of subjecting the samples to deep UV (185 nm) radiation, generation efficiency was found to be independent of whether Sb(III), Sb(V) or organometallic species [trimethyltantimony(V)dibromine, TMSb(V)], eliminating the shortcoming of Sb species depended sensitivity encountered during direct solution nebulization by ICPMS. Furthermore, the potentially severe matrix effect from seawater was efficiently eliminated by using a mixture of 5% (v/v) formic and 15% acetic acids (v/v) as the photochemical reductant, making direct determination of Sb in seawater feasible. The proposed method provides a 15-fold improvement in sensitivity over direct solution nebulization. A method detection limit of 0.0006 ng g-1 ba...
Journal of Chromatography A, 2015
Determination of thiocyanate in saliva by headspace gas chromatography-mass spectrometry, followi... more Determination of thiocyanate in saliva by headspace gas chromatography-mass spectrometry, following a single-step aqueous derivatization with triethyloxonium tetrafluoroborate, Journal of Chromatography A (2015), http://dx.
Analytical chemistry, Jan 7, 2014
Atomization of bismuth hydride in a 17 W planar quartz dielectric barrier discharge (DBD) atomize... more Atomization of bismuth hydride in a 17 W planar quartz dielectric barrier discharge (DBD) atomizer was optimized and the performance of this device compared to that of a conventional quartz tube atomizer (QTA) for atomic absorption spectrometry (AAS). Modification of the inner surface of the DBD atomizer using dimethyldichlorsilane (DMDCS) was essential since it improved sensitivity by a factor of 2-4. Argon, at a flow rate of 125 mL min(-1), was the best DBD discharge gas. Free Bi atoms were also observed in the DBD with nitrogen, hydrogen, and helium discharge gases but not in air. The detection limit for Bi (1.1 ng mL(-1)) is worse than with the QTA (0.16 ng mL(-1) Bi). A poorer detection limit compared to a QTA is a consequence of the shorter optical path of the DBD. Moreover, the lower atomization efficiency and/or faster decay of free atoms in the DBD has to be considered. The performance of the DBD as an atomizer reflects both effects, i.e., atomization efficiency and free at...
Analytical Chemistry, 2015
A novel and sensitive approach for the accurate and precise determination of Pb in environmental ... more A novel and sensitive approach for the accurate and precise determination of Pb in environmental samples is presented using transition metal ion-assisted photochemical vapor generation (PVG) for sample introduction with multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) detection. A significant improvement in PVG efficiency of lead is achieved in the presence of transition metal ions (Co(2+) and Ni(2+)) in solutions of 5% (v/v) formic acid. The determination of Pb in digests of sediment or soil samples is readily achieved due to coexisting transition metal ions which facilitate the PVG reaction. The method detection limit of 0.005 ng g(-1) (3σ) using external calibration is comparable to that obtained using hydride generation (HG) ICPMS. However, PVG methodology is simpler, results in lower blanks, and avoids unstable reagents. The accuracy of the proposed method was demonstrated by analysis of several environmental certified reference materials (CRMs; SLRS-5 and SRM1640a river water CRMs and MESS-3, MESS-4, and SRM2702 sediments) with satisfying results. High precision of determination (<0.4% RSD) of Pb in river water and sediments was realized on the basis of isotope dilution calibration.
ABSTRACT Strontium Isotope Amount Ratios in a Biological Tissue as Candidate Reference Material u... more ABSTRACT Strontium Isotope Amount Ratios in a Biological Tissue as Candidate Reference Material using MC-ICPMS
ABSTRACT Two different highly homogenised fly ash materials, originating from municipal city wast... more ABSTRACT Two different highly homogenised fly ash materials, originating from municipal city wastes and sewage sludges, have been analysed for the total content of six elements (Cd, Cr, Cu, Ni, Pb and Zn). The distribution of these six metals among different fractions has been investigated as well, by applying a 3-step sequential extraction procedure proposed by the Standards, Measurements and Testing program (SM&T) of the European Union, in order to achieve information on the potential mobility of these metals from the two considered materials. Metal behaviour during the sequential extraction has resulted to be more related to the material origins than to their total content in the matrix.
A simple, rapid, and sensitive method, which allowed us to simultaneously determine seven benzodi... more A simple, rapid, and sensitive method, which allowed us to simultaneously determine seven benzodiazepines (diazepam, nordiazepam, temazepam, oxazepam, 7-aminoflunitrazepam, N-desmethylflunitrazepam, and clonazepam) in buffer solution and in urine and serum samples, was investigated by automated in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS). In-tube SPME, in which the analytes were extracted from the sample directly into
Analytical chemistry, Jan 9, 2015
A novel and sensitive approach for the accurate determination of Sb in natural waters is describe... more A novel and sensitive approach for the accurate determination of Sb in natural waters is described using photochemical vapor generation (PVG) coupled with inductively coupled plasma mass spectrometry (ICPMS) for detection. Utilizing a unique flow-through photochemical reactor capable of subjecting the samples to deep UV (185 nm) radiation, generation efficiency was found to be independent of whether Sb(III), Sb(V) or organometallic species [trimethyltantimony(V)dibromine, TMSb(V)], eliminating the shortcoming of Sb species depended sensitivity encountered during direct solution nebulization by ICPMS. Furthermore, the potentially severe matrix effect from seawater was efficiently eliminated by using a mixture of 5% (v/v) formic and 15% acetic acids (v/v) as the photochemical reductant, making direct determination of Sb in seawater feasible. The proposed method provides a 15-fold improvement in sensitivity over direct solution nebulization. A method detection limit of 0.0006 ng g-1 ba...
Journal of Chromatography A, 2015
Determination of thiocyanate in saliva by headspace gas chromatography-mass spectrometry, followi... more Determination of thiocyanate in saliva by headspace gas chromatography-mass spectrometry, following a single-step aqueous derivatization with triethyloxonium tetrafluoroborate, Journal of Chromatography A (2015), http://dx.
Analytical chemistry, Jan 7, 2014
Atomization of bismuth hydride in a 17 W planar quartz dielectric barrier discharge (DBD) atomize... more Atomization of bismuth hydride in a 17 W planar quartz dielectric barrier discharge (DBD) atomizer was optimized and the performance of this device compared to that of a conventional quartz tube atomizer (QTA) for atomic absorption spectrometry (AAS). Modification of the inner surface of the DBD atomizer using dimethyldichlorsilane (DMDCS) was essential since it improved sensitivity by a factor of 2-4. Argon, at a flow rate of 125 mL min(-1), was the best DBD discharge gas. Free Bi atoms were also observed in the DBD with nitrogen, hydrogen, and helium discharge gases but not in air. The detection limit for Bi (1.1 ng mL(-1)) is worse than with the QTA (0.16 ng mL(-1) Bi). A poorer detection limit compared to a QTA is a consequence of the shorter optical path of the DBD. Moreover, the lower atomization efficiency and/or faster decay of free atoms in the DBD has to be considered. The performance of the DBD as an atomizer reflects both effects, i.e., atomization efficiency and free at...
Analytical Chemistry, 2015
A novel and sensitive approach for the accurate and precise determination of Pb in environmental ... more A novel and sensitive approach for the accurate and precise determination of Pb in environmental samples is presented using transition metal ion-assisted photochemical vapor generation (PVG) for sample introduction with multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) detection. A significant improvement in PVG efficiency of lead is achieved in the presence of transition metal ions (Co(2+) and Ni(2+)) in solutions of 5% (v/v) formic acid. The determination of Pb in digests of sediment or soil samples is readily achieved due to coexisting transition metal ions which facilitate the PVG reaction. The method detection limit of 0.005 ng g(-1) (3σ) using external calibration is comparable to that obtained using hydride generation (HG) ICPMS. However, PVG methodology is simpler, results in lower blanks, and avoids unstable reagents. The accuracy of the proposed method was demonstrated by analysis of several environmental certified reference materials (CRMs; SLRS-5 and SRM1640a river water CRMs and MESS-3, MESS-4, and SRM2702 sediments) with satisfying results. High precision of determination (<0.4% RSD) of Pb in river water and sediments was realized on the basis of isotope dilution calibration.
ABSTRACT Strontium Isotope Amount Ratios in a Biological Tissue as Candidate Reference Material u... more ABSTRACT Strontium Isotope Amount Ratios in a Biological Tissue as Candidate Reference Material using MC-ICPMS
ABSTRACT Two different highly homogenised fly ash materials, originating from municipal city wast... more ABSTRACT Two different highly homogenised fly ash materials, originating from municipal city wastes and sewage sludges, have been analysed for the total content of six elements (Cd, Cr, Cu, Ni, Pb and Zn). The distribution of these six metals among different fractions has been investigated as well, by applying a 3-step sequential extraction procedure proposed by the Standards, Measurements and Testing program (SM&T) of the European Union, in order to achieve information on the potential mobility of these metals from the two considered materials. Metal behaviour during the sequential extraction has resulted to be more related to the material origins than to their total content in the matrix.