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ABSTRACT: In the framework of a certification campaign organized by BCR (Bureau Communautaire de Référence, Commission of the European Communities, Brussels) molybdenum was determined in a sea water candidate reference material (BCR CRM 403) using inductively coupled plasma-mass spectrometry. The determination was hampered by both non-spectral (signal suppression) and spectral interferences. Ten-fold dilution of the sea water and the use of a carefully selected internal standard allowed accurate correction for the signal suppression. Spectral interferences on Mo nuclides could mainly be attributed to BrO(+) and BrOH(+) ions. At the level of spectral overlap encountered, these interferences could be corrected for with sufficient accuracy by matrix matching of the blank for Br or by application of a mathematical correction method involving resolvation of a pair of simultaneous equations. Results obtained after application of anion exchange to separate Br from Mo confirmed the results obtained using the correction methods, proving the validity of the latter. A good agreement is established by comparison of the ICP-MS result with those obtained by other techniques in other laboratories.
Talanta 08/1993; 40(7):975-9. · 3.79 Impact Factor
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ABSTRACT: Careful study of the matrix effect in ICP-MS showed that, in all cases studied, the magnitude of the signal suppression or enhancement depends in a regular way on the mass number. Hence, accurate correction for non-spectral interferences is only possible using an internal standard with mass number close to that of the analyte element(s). It is also shown that using an internal standard with mass number close to that of the analyte improves the precision. For both cases, the ionization energy of the internal standard seems to be of no or only secondary importance. To obtain optimal precision and accuracy, the internal standard should be selected as close in mass number as possible to that of the analyte element(s). When a number of elements over a considerable mass range are to be determined, several internal standards have to be used.
Talanta 08/1992; 39(7):737-42. · 3.79 Impact Factor
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Analytical Letters 05/1992; 25(5):919-936. · 1.02 Impact Factor
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ABSTRACT: Strontium has been determined in a human serum reference material by ICP-MS and by NAA. By ICP-MS, results for (88)Sr and (86)Sr in both 10- and 5-fold diluted serum were in good agreement. For (88)Sr the precision was better than 3% and the detection limit was 0.05 mug/l. under the conditions used. The results were 25.5 mug/l. in the liquid serum or 0.281 mug/g in the lyophilized reference material. In the NAA the (87m)Sr produced was radiochemically separated by extraction with oxine in chloroform. The precision was about 10% and the detection limit 0.02-0.05 mug/g.
Talanta 09/1990; 37(8):819-23. · 3.79 Impact Factor
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ABSTRACT: A method is described for the determination of mercury in human blood serum and packed blood cells employing neutron activation analysis. Great attention was devoted to the collection and manipulation of the samples. The accuracy and precision of the method were tested by analyzing biological reference materials and by comparing the concentrations measured in a number of serum samples to those obtained by another, independent technique (cold vapor atomic absorption spectrometry) in the same samples. The article reports the levels measured in blood serum and packed blood cells samples from 15 adult volunteers, as well as the figures determined in a "second-generation" biological reference material (freeze-dried human serum), prepared and conditioned at the University of Ghent.
Biological Trace Element Research 04/1990; 26-27:683-9. · 1.92 Impact Factor
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ABSTRACT: Enrichment on Chelex-100, followed by evaporation when necessary, was used for the pre-concentration of Cd, Pb, Cu and Zn from natural waters. The measurements were carried out with inductively coupled plasma atomic emission spectrometry using a thermospray nebulisation system to reach the required sensitivity. The detection limits corresponding to three times the standard deviation of the blank (in 1% v/v HNO3) after a 30-fold enrichment are 0.02 microgram l-1 for Cd, 0.33 microgram l-1 for Pb and 0.03 microgram l-1 for Cu and Zn. Matrix effects, which are fairly serious with thermospray nebulisation, were taken into account by using the standard additions method. Results obtained for several river water samples were compared with those found by analysis of the non-enriched sample with inductively coupled plasma mass spectrometry or graphite furnace atomic absorption spectrometry. In all instances the agreement was satisfactory.
The Analyst 02/1990; 115(1):17-22. · 4.23 Impact Factor
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ABSTRACT: A method was developed for the determination of seven trace elements (Fe, Co, Cu, Zn, Rb, Mo, and Cs) in human serum by inductively coupled plasma mass spectrometry (ICP-MS). Sample preparation was kept as limited as possible. As the only sample pretreatment serum samples were diluted with nitric acid and indium was added as an internal standard. The results for iron, cobalt, copper, and zinc were corrected for interferences from polyatomic ions by using a blank solution containing the same concentration of sodium, sulfur, chlorine, and calcium as human serum. For copper and zinc the corrections are small, whereas for iron and cobalt they are important. No interferences occur for the considered isotopes of rubidium, molybdenum, and cesium. In order to test the accuracy and precision of the analytical technique, a "second-generation biological reference material (human serum)" was analyzed. The results obtained by ICP-MS for the seven elements considered showed good agreement with the certified values.
Analytical Chemistry 10/1989; 61(17):1851-7. · 5.86 Impact Factor
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ABSTRACT: Elemental emissions during firing in a shooting range were measured for different types of ammunition. When using Hirtenberger bullets, lead, barium, antimony and to a lesser extent copper and arsenic were the primary metal pollutants. Stationary sampling at three locations in the range did not reveal large concentration gradients. Large concentration variations were observed by sampling before, during and after shooting. Lead and antimony concentrations peak at 5060 and 119 micrograms m-3, respectively. Soil elements such as aluminium, sodium and calcium are enriched during shooting, probably due to soil resuspension by the shooters and the bullets hitting the sand backstop. After shooting has ceased the concentrations fall to within pre-shooting levels within a couple of hours. Measurement of the aerodynamic particle size shows low mass median diameters for the elements emitted during firing and larger diameters for the soil-associated elements. The peak airborne concentrations measured by stationary sampling, and human exposure measured by a personal sampler carried by an instructor were compared with threshold limit values. During the shooting the TLV is significantly exceeded for lead.
Science of The Total Environment 12/1988; 77(1):1-13. · 3.29 Impact Factor
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ABSTRACT: The determination of boron, carbon, nitrogen and oxygen in nickel by charged particle activation using the reactions 10B(d, n)11C, 12C(d, n)13N, 14N(p, )11C and 16O(3He, p)18F is studied. The interference of 11B(p, n)11C with the 14N(p, )11C reaction is taken into account. 11C, 13N and 18F are separated by oxygen combustion followed by trapping of 11CO2 in NaOH and by steam distillation of 13NH3 and of H2Si18F6, respectively. The results obtained were 0.1290.035 g g–1 for boron, 86.48.3 g g–1 for carbon, 1.0770.037 g g–1 for nitrogen and 8.911.00 g g–1 for oxygen. The results for nitrogen and oxygen agreed satisfactorily with those of other analytical methods.Folgende Reaktionen wurden untersucht: 10B(d,n)11C, 12C(d,n)13N, 14N(p,)11C, 16O(3He, p)18F. Die Strung der Reaktion 14N(p, )11C durch 11B(p, n)11C wurde bercksichtigt. 11C, 13N und 18F werden durch Sauerstoffverbrennung getrennt, wobei 11CO2 in NaOH absorbiert wird und 13NH3 bzw. H2Si18F6 durch Wasserdampfdestillation abgetrennt werden. Folgende Ergebnisse wurden erhalten: 0,1290,035 g/g fr B; 86,48,3 g/g fr C; 1,0770,037 g/g fr N; 8,911,00 g/g fr O. Die Ergebnisse fr Stickstoff und Sauerstoff stimmten gut mit denen anderer Methoden berein.
Fresenius Journal of Analytical Chemistry 12/1979; 303(2):106-110.
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ABSTRACT: A method was developed for the determination of mercury in air, using preconcentration by amalgamation on gold absorbers followed by measurement by atomic fluorescence spectrometry (AFS). The system has a detection limit of ca. 2.0 pg and the precision is in the range 5–10% (relative standard deviation). The accuracy was confirmed by comparison with cold vapour atomic absorption spectrometry. The method was applied to the determination of gaseous mercury in both indoor and outdoor air. As a result of the sensitivity small sample volumes can be analysed and only short sampling times are required. The method is thus suitable for continuous monitoring of mercury and for the fast and reliable determination of gaseous mercury in the atmosphere, even at background levels.
Analytica Chimica Acta.
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ABSTRACT: Microwave dissolution in closed teflon vessels is described for the determination of ng g−1 contents of mercury in biological materials, prior to two-stage gold amalgamation and cold-vapour atomic absorption spectrometry. Six samples can be decomposed simultaneously within 20 min, with a preset heating programme. The detection limit is 0.84 ng g−1 for a 100-mg sample. Results for six certified reference materials agreed with the certified values.
Analytica Chimica Acta. 220:257-261.
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ABSTRACT: The determination of trace and ultratrace elements in human serum by ICP-MS is described. The accuracy of the method is tested using a "second generation" human serum reference material. Elements determined include Fe, Co, Cu, Zn, Br, Rb, Sr, Mo, and Cs. The method is compared to nuclear analytical methods (NAA, PIXE). Perspectives for the future are also discussed.
Biological Trace Element Research 26-27:553-60. · 1.92 Impact Factor
