Major and trace element characterization of prehistoric ceramic from Rezende archaeological site

Forty one ceramic fragment samples from Rezende archaeological site, Centralina city, Minas Gerais State, Brazil, were analyzed using INAA to determine the concentration of 24 chemical elements: As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn. Three multivariate statistical methods, cluster, discriminant and principal components analysis were performed on the data set. The results showed that the large majority of the samples (94%) can be considered to be manufactured using the same source of raw material.     

Major and trace elements in sediments of the upper course of Lerma river

Summary The Lerma is one of the most important rivers of Mexico, where it drains highly populated and industrialized regions. The concentration of six major and trace elements: titanium, manganese, iron, zinc, copper and lead in the surface sediments of the upper course of Lerma river was investigated, in order to identify its distribution along the river and to recognize the principal sites of pollution. The surface sediment samples were collected at 8 sites distributed following the stream flow direction of the river. Major and trace elements concentrations were determined by energy dispersive X-ray spectrometry. The results show that the metal concentrations in the sediments decrease in the sequence: Fe > Ti > Mn > Zn > Cu > Pb. Concentration of Fe, Mn and Ti were significantly higher than the other metals in site 8,200 meters downstream the Alzate Dam. The high concentrations and spatial variations of Zn, Cu and Pb in the middle sites of the upper course of the Lerma River indicate that the river pollution is probably associated with urban and industrial discharges.     

Human albumin as a reference material for trace elements

Summary An investigation through interlaboratory comparison using different analytical techniques has been carried out in order to assess the suitability of a plasma protein solution as a source for a trace element reference material in clinical analysis. Reasonable agreement was obtained for a number of elements from the range studied: Al, Ba, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Se, Sr, V and Zn. The techniques used included flame and furnace atomic absorption spectrometry (FAAS and ETA-AAS), furnace atomic emission spectrometry (ETA-AES), inductively coupled plasma atomic emission spectrometry (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), and simultaneous multi-element atomic absorption spectrometry (SIMAAC). Results indicated that this plasma protein solution may prove useful as a source for a reference material covering trace element levels outwith the range found in normal human plasma.

---

Humanalbumin als Referenzmaterial für Spurenelemente

     

Mushrooms as biological monitors of trace elements in the environment

Mushrooms as a functional system relating to the most important environmental compartments (soil, water, air), may be used advantageously as biological monitors of the state of the environment. In particular the aerial parts of the mushroom (head and stem), because of their rapid growth rate from a few days to a few weeks, could be a useful indicator of fluctuations that may occur in the ecosystem. In this study the levels of fallout radionuclides¹³⁴Cs,¹³⁷Cs, due mostly to the Chernobyl nuclear accident, of natural radionuclide⁴⁰K and of the stable elements Se, Hg, Cr, Cs, Sc, Rb, Zn, Fe, Co, Eu, Sb, Ag, Ce, Ba, Ni present in the head and stem of mushroom samples from an area of the Italian Alps were measured. The analytical technique used was Instrumental Neutron Activation Analysis and gamma-spectrometry. The results are discussed and possible correlations with other environmental parameters are examined.     

Determination of trace elements by INAA in urban air particulate matter and transplanted lichens

Summary Lichens as biomonitors and neutron activation analysis as analytical technique have been employed to evaluate the trace element atmospheric pollution in the metropolitan area of the city of Pavia (Northern Italy). Transplanted lichens (Parmelia sulcata and Usnea gr. hirta) and air particulate matter have been monthly collected and analyzed during the winter 2001-2002. INAA and ET-AAS have been used for the determination of 28 elements in air particulate matter and 25 elements in lichens. Trace metals concentrations as well as the corresponding enrichment factors were evaluated and compared.     

Honey as a candidate reference material for trace elements.

The feasibility of producing and certifying new certified reference materials (CRMs) for trace elements in honey was investigated. Preliminary steps for preparation of candidate materials are performed at the Institute for Reference Materials and Measurements, Joint Research Centre of the European Commission (EC-JRC-IRMM). Two different types of honey, Acacia and Eucalyptus, were tested for determination of 10 trace elements. To each type of honey was added a given amount of high purity deionized water to obtain aqueous solutions with an acceptable degree of homogeneity which would require only minimal manipulation before analysis. Average values obtained for the trace elements by means of inductively coupled plasma-based techniques were as follows (in microg/ kg +/- SD): Acacia honey, As, 1.10+/-0.20; Cd, 0.328+/-0.035; Cr, 1.90+/-0.22; Cu, 67.0+/-5; Fe, 215+/-30; Hg, < 0.75; Mn, 82.1+/-6.2; Ni, 21.0 3.0; Pb, 2.30+/-0.25; Se, 9.10+/-1.2; Zn, 167+/-22; Eucalyptus honey, As, 5.99+/-0.10; Cd, 0.592+/-0.074; Cr, 1.50+/-0.07; Cu, 219 24; Fe, 1008+/-114; Hg, <0.75; Mn, 1009+/-51; Ni, 11.3+/-1.5; Pb, 5.00+/-0.40; Se, 5.60+/-0.91; Zn, 791+/-91. When these 2 pilot materials are ready, the certification project will be launched in full compliance with current rules set by EC-JRC-IRMM. If the project is successful, the new CRMs will be put primarily at the disposal of the National Reference Laboratories for trace elements.     

Size spectra for trace elements in urban aerosol particles by instrumental neutron activation analysis

Size-fractionated aerosol samples collected with micro-orifice impactors at Camden, NJ, a heavily industrialized urban area, and at two sites near Washington, DC, were analyzed for elemental constituents determined instrumentally from short-lived neutron activation products. A least-squares peak-fitting method was used with impactor calibration data to determine log-normal distribution parameters, i.e., mass median aerodynamic diameter (MMAD) and geometric standard deviation (_g) for particles bearing S, V, Br, and I. For these elements, MMADs ranged from 0.24 to 0.65 m; 0.23 to 0.53 m; 0.22 to 0.61 m, and 0.20 to 0.48 m, respectively.     

Use of Spanish Moss as an atmospheric monitor for trace elements

Samples of Spanish Moss (Tillandsia usneoides L.) were analyzed by neutron activation analysis (NAA) and inductively coupled argon plasma emission spectrometry (ICP) for trace elements as atmospheric environmental monitors. The plant material was collected at a single location in east Texas, then deployed along a 6×6 matrix gridwork in the extreme northeastern corner of the state. The study area includes several possible pollution sources including fossil fuel fired power plants. Two separate study periods were conducted, one during the summer months of 1989 and the other the following winter. Concentrations of about 35 elements were determined and contour plots for each element were pepared for each study period. Concentration ranges were found to be somewhat lower than those reported in other studies using epiphytic plants as environmental indicators. Initial correlations between elements and the possible relationships to pollution sources are discussed.     

Solid phase microextraction as a tool for trace element speciation

Applications of solid phase microextraction (SPME) for trace element speciation are reviewed. Because of the relative novelty of the technique in the inorganic analytical field, the first part of this review provides a short overview of the principles of SPME operation; the second part describes typical SPME applications to elemental speciation. Volatile organometallic compounds can be collected by SPME from the sample headspace or liquid phase, directly or after derivatization. The usual separation method for the collected volatile species is gas chromatography. Non-volatile analyte species can be collected from the sample liquid phase and separated by liquid chromatography or capillary electrophoresis. Currently, most SPME applications in the inorganic field comprise analyte ethylation and headspace extraction followed by gas chromatographic separation of tin, lead and mercury species. The use of SPME for the study of equilibria in complex systems is also discussed and future roles of solid phase microextraction in the inorganic analytical field are raised.     

Search for a possible correlation between geographical area of domicile and trace element composition of human blood serum as determined by pixe

An investigation was undertaken to measure the trace elements in the blood samples by particle induced X-ray emission (PIXE). From the measured concentrations an attempt was made to group the blood specimens by pattern recognition methods as a first step in the search for a possible correlation between the geographical area of domicile and trace elemnt composition. The trend indicated that children with lower Fe and Br contents were similar in their trace element pattern, were predominantly from two district, had lower ferritin values and were breast fed longer than the remaining children in the survey.     

Availability of essential trace elements in medicinal herbs used for diabetes mellitus and their possible correlations

Four plant parts (leaves, roots, fruits and seeds) of twenty samples of sixteen antidiabetic herbs including three commercially marketed capsules have been analyzed for 6 minor (Na, K, Ca, Cl, Mg, and P) and 21 trace (As, Ba, Br, Ce, Co, Cr, Cs, Cu, Eu, Fe, Hg, La, Mn, Rb, Sb, Sc, Se, Sm, Th, V and Zn) elements by instrumental neutron activation analysis (INAA). Further, Ni, Cd and Pb contents were determined by AAS. Elemental data were validated by simultaneously analyzing reference material (RM), MPH-2 Mixed Polish Herbs. Several elements such as Cr and V (1–2 μg/g), Rb (10–40 μg/g), Cs (80–300 ng/g), Se (∼100 ng/g) and Zn (25–60 μg/g) play an important role in diabetes mellitus. Interelemental linear correlations have been observed for Cu vs. Zn (r = 0.89) and Rb vs. Cs (r = 0.87). K/P ratio varies in a narrow range with a mean value of 6.2 ± 1.4. Toxic elements As and Hg were found in <1 μg/g whereas Cd and Pb were in ∼5 μg/g and <10 μg/g, respectively.     

Unloaded polyether type polyurethane foams as solid extractants for trace elements

Polyether type polyurethane foams (PU) are regular stacks of solid quasi-spherical membranes produced by the reaction of polyisocyanates with polyols of polyether nature in the presence of a catalyst and a blowing agent. Contrary to conventional membrane separations, where a solid membrane is merely a differentially separating agent, or a transport medium, PU foams, apart from separation and preconcentration, also retain, i.e., sorb the species on, or in the membranes. Therefore, PU foam membranes can be considered to act as true sorbents. The membrane properties of PU foam sorbents offer unique advantages over conventional bulk type granular sorbents in rapid, versatile and effective separations and preconcentrations of different compounds from fluid samples. Unloaded PU foam sorbents have received considerable attention in the separation of different trace inorganic species.     

Determination of trace elements in wool fibre by instrumental neutron activation analysis and relation between trace element contents and quality of wool

Synergistic extraction of uranyl ion with 2-thenoyltrifluoroacetone (HTTA) and aliphatic amides with varying basicities, viz. dibutyl hexanamide (DBHA), dibutyloctanamide (DBOA) or dibutyldecanamide (DBDA) has been studied at various fixed temperatures of 20, 30, 40 and 50±0.1°C. Results indicate that the equilibrium constants of the organic phase addition reaction (Ks) with these amides follow their order of basicity (Kh) viz. DBHA (0.09)<0.10) H DBOA (0.13) with log Ks values of 4.91, 4.99 and 5.02, respectively. These values are much higher than those with TBP (3.8) or sulfoxides (4) as donors. This may be attributed to the existence of a resonance form of the amide, which has higher electron density on the carbonyl oxygen. The thermodynamic parameters associated with these systems evaluated by the temperature coefficient method indicate that the organic phase addition reaction with all the three amides is stabilized by both enthalpy and entropy changes as against UO ₂ ²⁺ /HTTA/TBP system, where only the enthalpy change contributes to the stabilization.     

Determination of trace elements in hair from Tanzanian children: Effect of dietary factors

The objective of this study was to evaluate the concentrations of essential and toxic elements in hair of children in Tanzania in order to assess their nutritional status. 141 samples of hair from boys and girls living in Tanzania were analyzed using instrumental neutron activation analysis (INAA). The mean concentration levels of Zn and Cu were lower whilst those of other elements were in the same range as the hair elemental concentrations reported in the literature. The lower concentrations of Zn might be related to the diet of mainly cereals with low animal proteins consumed by most of the Tanzanian population.     

Solid-liquid extraction as a preconcentration technique in trace element analysis Extraction of trace impurities from metal chlorides

Microgram quantities of iron, cobalt, copper, zinc and cadmium are extracted with various aqueous, organic and mixed solvents from chlorides of sodium, potassium, nickel, cadmium, barium and lead prepared by evaporation of aqueous sample solutions. An ultrasonic field accelerates the extraction, and satisfactory trace recoveries and separation factors are achieved in several systems within a reasonable time. The application to a polarographic determination and a two-stage separation technique are also described.     

Evaluation of residual fuel oil standard reference materials as trace element standards

National Bureau of Standards residual fuel oil Standard Reference Materials, SRM 1619, 1620a, 1634a, and former SRM 1634 were analyzed for 20 trace elements by instrumental neutron activation analysis to determine whether these materials are suitable trace element standards for elements other than the 6 elements certified in SRM 1634a. The SRM 1634a is a suitable standard for Ni, V, Se, Na, Zn, As, Cr, Fe, Ce, Sm and La but Co, Ba, Nd, Cs, Eu, Sc, and Sb appear to be heterogeneously distributed and are probably present in mineral particulates. The SRM 1619 is a convenient standard for V and for low Ni content oils, but SRM 1620a does not appear to be a suitable standard for any trace element investigated.To whom correspondence should be addressed.     

Concentration of analytical data as part of data processing in trace element analysis

Summary Statistical data evaluation in trace element analysis was mainly influenced by the Normal Law of Error, which is based on the assumption of a Gaussian normal distribution. Supposing that the analytical error of the trace element concentration is negligibly small compared with its true variations in nature, skew distributions may become more important than normal ones. Often, but not always, the lognormal distribution is a good approximation of the skew distribution. Careful investigation of the type of distribution before starting data evaluation in trace element analysis is still frequently overlooked today.In this Department, data concentration is performed on a routine basis by two programmes ZCH-2 and ZCH-3/1. They include a) investigation of the type of distribution by drawing the histogrammes, probability plot for normal and lognormal distribution as Hazen's straight lines, Kolmogorov-Smirnov- and Cramer- van Mises goodness-of-fit tests as well as skewness and kurtosis. Outliers of the normal distribution can be eliminated b) by t-, Nalimov's r-, Grubb's and Dixon's tests. c) As central values for data location, the arithmetic, geometric, and harmonic means and median are calculated. d) The dispersion around the mean is characterized by variance, standard deviation of a single value as well as the mean, relative coefficient of variation, mean deviation from the arithmetic mean, geometric standard deviation, range and 80% inter-decile range. Confidence intervals are given for the arithmetic mean, geometric mean and median.Typical problems of data concentration are the deviation from the normal distribution, comparison of different mean values, outlier elimination, concentrations below detection limit, homogeneity and heterogeneity of the data sample. They are discussed for examples of data series from one of the author's laboratories, e.g. trace element concentrations in air, lead content in dental calculus, toxic heavy metal leaching from ceramic ware and gamma dose rates from an area of higher natural radioactivity in the Federal Republic of Germany.As a conclusion, it is emphasized that the trace element analyst should overcome the Mystery of the Normal and Quasi-normal Distribution and include skew data distributions and their statistical treatment into his repertoire of routine procedures as well as in his way of thinking.

---

Konzentrierung analytischer Daten als Teil der Datenverarbeitung in der Spurenelementanalyse

Zusammenfassung Die statistische Beurteilung von Daten der Spurenelementanalyse war lange Zeit durch das Gesetz der Fehler-Normalverteilung geprägt, welches auf der Annahme einer Gaußschen Normalverteilung beruht. Wird der analytische Fehler der Konzentrationsbestimmung von Spurenelementen vernachlässigbar klein gegenüber den tatsächlichen Schwankungen in der Natur, dann werden schiefe Verteilungen häufig wichtiger als Normalverteilungen. Eine gute Näherung ist oft, allerdings nicht immer, die Lognormalverteilung. Der Spurenanalytiker übersieht häufig auch heute noch, vor Beginn der eigentlichen Datenbeurteilung den Typ der vorliegenden Häufigkeitsverteilung seines Datensatzes zu untersuchen.Die Datenkonzentrierung erfolgt in der hiesigen Zentralabteilung routinemäßig vor allem mit den Programmen ZCH-2 und ZCH-3/1. Darin wird der Typ der Datenverteilung a) durch Zeichnen der Histogramme, Auftragung als Hazens Gerade in Wahrscheinlichkeitskoordinaten für Normal- und Lognormalverteilung, den Kolmogorov-Smirnov- und Cramer-van-Mises-Anpassungstests sowie Schiefe und Wölbung beurteilt. Bei Quasi-Normalverteilungen können b) Ausreißer durch den t-, Nalimovs r-, Grubbs- und Dixon-Test eliminiert werden. Zentralwerte zur Lokalisierung des Datenkollektives sind c) arithmetisches, geometrisches und harmonisches Mittel sowie Median. Die Streuung um die Mittelwerte wird durch d) Varianz, Standardabweichung für Einzelwert sowie Mittel, relativen Variationskoeffizienten, geometrische Standardabweichung, Bereich und 80% Interdezil-Bereich charakterisiert. Zusätzlich werden Vertrauensbereiche für das arithmetische und geometrische Mittel und den Median berechnet.Als typische Probleme der Datenkonzentrierung werden die Abweichungen von der Normalverteilung, ein Vergleich verschiedener Mittelwerte untereinander, die Eliminierung von Ausreißern, die Behandlung von Konzentrationen unterhalb der Nachweisgrenze sowie Homogenität und Heterogenität der Datenkollektive behandelt. Dies wird an Datenreihen aus früheren Untersuchungen eines der Verfasser über Spurenelementkonzentrationen in der Luft, den Bleigehalt in Zahnstein, die Auslaugung toxischer Schwermetalle aus Keramikgeschirr und Gamma-Dosisleistungen aus einem Gebiet der Bundesrepublik mit höherer natürlicher Untergrundradioaktivität erläutert.Als wesentliches Ergebnis soll die Arbeit dazu beitragen, daß der Spurenanalytiker das Mysterium der Normalverteilung überwindet und die Behandlung schiefer Datenverteilungen sowohl in das Repertoire seiner Routineuntersuchungen als auch in sein analytisches Denken aufnimmt. Um einen größeren Kreis von Spurenanalytikern anzusprechen, ist die Darstellung elementar gehalten.

Dedicated to Prof. Dr. E. Blasius, on occasion of his 60th birthday