Peter Ostapczuk

Determination of selected trace elements in herbs and their infusions.

The following macro- and microelements were determined in the leaf of peppermint (Mentha piperitae folium) and nettle (Urticae folium) (as tea bags) and in their infusions: As, Ba, Ca, Cd, Co, Cr, Cu, Fe, I, Li, Mg, Mn, Ni, Pb, Se, Sn, Sr, Ti, V and Zn. The determinations were performed using inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS). From all the determined microelements the highest content found was that of iron, 244 and 107 mg/kg in the leaf of peppermint and nettle, respectively. However, the lowest content found was that of cobalt, 0.10 and 0.08 mg/kg for the leaf of mint and nettle, respectively. The most readily water eluting elements were strontium, selenium and iodine, the most difficult ones - barium and iron.

Total arsenic, lead, and cadmium levels in vegetables cultivated at the Andean villages of northern Chile.

Various vegetables (broad beans, corn, potato, alfalfa and onion) were sampled in northern Chile, Antofagasta Region. They are the basis of human nutrition in this region and of great relevance to human health. This region is characterized by volcanic events (eruptions, thermal springs, etc.). Most of the vegetables cultivated in this area enter the local markets for a population of approximately 4000 people, whose ancestors were mainly atacameños and quechuas (local indigenous people). The cadmium and lead in these foods was determined by differential pulse anodic stripping voltammetry (DPASV). Results indicate that the highest concentration of Pb and Cd are in the potato skin, while the edible part of the potatoes contained a lower concentration of these metals. The INAA analyses of As in the vegetables from Socaire and Talabre, two towns located close to active volcanoes (e.g. Lascar), show a very high As content: 1850 microg/kg in corn (Socaire) and 860 microg/kg in potatoes (+ skin) (Talabre). These values exceed the National Standard for arsenic (500 microg/kg) by approximately 400% and 180%, respectively. In general, the data show a concentration of Pb greater than Cd with the potential for some vegetables to accumulate heavy metals, The values, expressed in fresh weight, vary from 0.2 to 40 microg/g for Cd and from 0.6 to 94 microg/g for Pb. These concentration intervals, except that of arsenic, are within the recommended standards in the Food Sanitary Regulation (Decree 977), which, expressed as fresh weight, must be equal to or smaller than 500 microg/kg for Pb. There is no legal standard for Cd.

Potentiometric stripping determination of mercury(II), selenium(IV), copper(II) and lead(II) at a gold film electrode in water samples

Abstract A potentiometric stripping method for the determination of Se(IV), Hg(II) at the ng 1 −1 level, which also permits the simultaneous determination of Cu(II) and Pb(II) has been developed. Anodic stripping by an oxidative constant current follows the reductive deposition of the elements in atomic form at a gold film working electrode. The performance of the method has been checked on a certified reference water sample. The method was adapted to operate on river water samples, and the results of the determination of mercury at low ng 1 −1 level in sea water are also reported. Typical interferences that can occur in water samples are discussed.

Statistical evaluation of ecosystem properties influencing the uptake of As, Cd, Co, Cu, Hg, Mn, Ni, Pb and Zn in seaweed (Fucus vesiculosus) and common mussel (Mytilus edulis)

In order to evaluate the influence of geographically varying marine ecosystem properties on the uptake of trace elements in bioindicators, samples were taken of seaweed (Fucus vesiculosus) and common mussel (Mytilus edulis) along the North Sea and Baltic Sea coast. Seasonal variations of the bioindicator status were minimized by sampling within 1 month. Ecosystem properties considered were the geographical position, the salinity and the concentrations of the macroelements Ca, Fe, K, Mg, Na, P and S in the bioindicators. Trace elements studied were As, Cd, Co, Cu, Hg, Mn, Ni, Pb and Zn. Factor analysis of the concentration patterns in the bioindicators and of salinity as a function of location confirmed the influence of the geographically varying salinity on the biological uptake of macroelements and trace elements. This influence of salinity was higher in the case of seaweed than in the case of mussel. Comparison of the geographical courses of the macroelement and trace-element concentrations by cluster analysis revealed corresponding courses for As and Hg in both bioindicators. All other elements showed different courses in seaweed and mussel. Subsequent cluster analysis comparing locations with respect to the macroelement or trace-element concentration patterns in the bioindicators, indicated a clear separation of North and Baltic Sea locations. However, the trace-element concentration patterns provided a regionally less distinctive ecosystem arrangement than those of the macroelement ones. The results of the cluster analysis were verified by discriminant analysis forming groups of locations with respect to geographical position and salinity. Results of discriminant analysis demonstrated, both for seaweed and for mussel as bioindicators, that the location groups formed according to the macroelement concentration patterns corresponded well with the geographical regions in the order of salinity. On the other hand, location groups based on the trace-element concentration patterns again showed a modified less distinctive ecosystem arrangement than the location groups based on macroelement concentration patterns. This confirms modified conditions for the uptake of trace elements in seaweed or mussel in comparison to the uptake of macroelements.

Development of frozen whale blubber and liver reference materials for the measurement of organic and inorganic contaminants

SummaryFresh frozen homogenates of pilot whale blubber and liver tissue were prepared for use as control materials for the determination of organic and inorganic contaminants in marine mammal tissue analyses. The blubber material was analyzed to determine 30 polychlorinated biphenyl congeners and 16 chlorinated pesticides using gas chromatography with electron capture detection and gas chromatographymass spectrometry. A total of 39 trace elements and methylmercury were determined in the liver homogenate using instrumental neutron activation analysis, voltammetry, and cold vapor atomic absorption spectroscopy. The preparation and analysis of these two tissue materials are part of the development of marine mammal tissue reference materials.

Determination of inorganic constituents in marine mammal tissues

Analyses of selected tissues from the Alaska Marine Mammal Tissue Archival Project (AMMTAP) have provided comprehensive information related to levels of 36 trace elements and methyl-mercury in marine mammal tissues. Liver, kidney and muscle tissues from two northern fur seals, four ringed seals and six belukha whales were analyzed. The bulk of the investigated tissues and additional tissues from a total of 65 marine mammals are banked in the AMMTAP. The results are compared to literature values for trace element concentrations in marine mammal tissues and their relevance to environmental studies is discussed.

Kontroll-und Routinebestimmung von Zn, Cd, Pb, Cu, Ni und Co mit differentieller Pulsvoltammetrie in Materialien der Deutschen Umweltprobenbank

SummaryA reliable procedure for the determination of the trace metals Zn, Cd, Pb, Cu, Ni and Co in materials of the German Environmental Specimen Bank by an advanced voltammetric method has been evaluated. Sample pretreatment is performed by wet digestion with HNO3/HClO4. The particular advantages of the described method are high sensitivity (especially for Ni and Co), good precision and relatively low cost of instrumentation. The accuracy of the results could be confirmed by IDMS and AAS.ZusammenfassungFür die voltammetrische Bestimmung der Schwermetalle Zn, Cd, Pb, Cu, Ni und Co in Materialien der Deutschen Umweltprobenbank wurde ein zuverlässiges Verfahren entwickelt. Die Probenvorbereitung besteht in einem Naßaufschluß mit HNO3/HClO4. Die Vorteile des beschriebenen Verfahrens liegen bei hoher Empfindlichkeit (besonders für Ni und Co), guter Präzision und relativ geringen Kosten für die Instrumentation. Die Richtigkeit der Ergebnisse wurde durch Vergleich mit IDMS und AAS bestätigt.

Kontroll- und Routinebestimmung von Zn, Cd, Pb, Cu, Ni und Co mit differentieller Pulsvoltammetrie in Materialien der Deutschen Umweltprobenbank@@@Control and routine determination of Zn, Cd, Pb, Cu, Ni, and Co with differential pulse voltammetry in materials of the German Environmental Specimen Bank

SummaryA reliable procedure for the determination of the trace metals Zn, Cd, Pb, Cu, Ni and Co in materials of the German Environmental Specimen Bank by an advanced voltammetric method has been evaluated. Sample pretreatment is performed by wet digestion with HNO3/HClO4. The particular advantages of the described method are high sensitivity (especially for Ni and Co), good precision and relatively low cost of instrumentation. The accuracy of the results could be confirmed by IDMS and AAS.ZusammenfassungFür die voltammetrische Bestimmung der Schwermetalle Zn, Cd, Pb, Cu, Ni und Co in Materialien der Deutschen Umweltprobenbank wurde ein zuverlässiges Verfahren entwickelt. Die Probenvorbereitung besteht in einem Naßaufschluß mit HNO3/HClO4. Die Vorteile des beschriebenen Verfahrens liegen bei hoher Empfindlichkeit (besonders für Ni und Co), guter Präzision und relativ geringen Kosten für die Instrumentation. Die Richtigkeit der Ergebnisse wurde durch Vergleich mit IDMS und AAS bestätigt.

Determination of chromium and selected elements in multimineral and multivitamin preparations and in pharmaceutical raw material.

The content of elements in pharmaceutical preparations is one of the indispensable factors of the evaluation of their quality. In the present work, the following macro- and microelements Ca, Cr, Cu, Fe, Mg, Mn, Mo, P, Se and Zn were determined in multimineral and multivitamin preparations and in pharmaceutical raw material. Inductively coupled plasma mass spectrometry (ICP-MS) and electrothermal atomic absorption spectrometry (ET AAS) were used throughout the study. The examined samples were dissolved in a high-pressure microwave system using concentrated nitric acid. The effect of the carbon residue in the digest solution on the determination result was eliminated by introducing an equation correcting the ArC+ interference with 52Cr.

Determination of arsenic species by field amplified injection capillary electrophoresis after modification of the sample solution with methanol

Organic solvent modification is investigated as a simple and effective way to decrease the conductivity of liquid samples containing anionic As species, making them suitable for field amplified sample stacking capillary electrophoresis (CE) measurements with direct UV detection. Experimental variables that influence the procedure, as buffer pH, stacking and running potential, are described for methanol, selected as the optimum sample modifier. The influence of modifying the CE buffer with methanol on the resolution is also discussed. Results of stacking with and without removing the sample matrix from the capillary (with and without polarity switching after the stacking stage) are reported. The optimized method permits the determination of As(III) (arsenite), free As(V) (arsenate), and dimethylarsinate (DMA), in the range from 0.5 to 20 mg/l, with detection limits around 0.3 mg/l. For other As(V) compound of human origin, phenylarsonate (PAA), and p-aminobenzenearsonate (PABA), the power of detection is higher due to their higher extinction coefficients. The linear range extends from 20 to 1000 μg/l, with a detection limit of 11 μg/l (PAA) and 16 μg/l (PABA).