Trace Elements In Biological Materials Research Articles

Scientific rationale for the indicators of biological urine monitoring in adolescents in Kazan City

BACKGROUND: Biomonitoring is crucial for assessing the level of pollution in a population, identifying risks and studying the impact of changes in technology. Knowledge of the reference values of trace elements in biological material is critical in comparing exposed with non-exposed groups and accurate. The control values of trace elements are crucial for ensuring public health and occupational safety. AIM: To study and analyze concentrations of priority chemical pollutants in the urine of adolescents aged 14–17 years in three zones in Kazan City and determine reference values for this age group. MATERIALS AND METHODS: The concentration of elements in urine of 276 adolescents aged 14–17 years was measured by inductively coupled plasma mass spectrometry. RESULTS: The upper 95 percentiles and their confidence intervals (RV95) were determined, which established the upper limit of the current background exposure to adolescents for 12 biomarkers, interpreted as “conditional” reference values for this age group. The following reference values for adolescents in Kazan City were obtained: Al, 12.80 µg/L; Cr, 1.02 µg/L; Mn, 3.53 µg/L; Hg, 0.65 µg/L; Cu, 110.91 µg/L, and Ni, 8.72 µg/L. In adolescents, the highest level of exceedance over background values was observed in zones 1 and 2 (Kirovsky and Privolzhsky Districts): Al exceeded by 1.4 times, Cr by 1.3 times in zone 1 (Kirovsky District), Mn by 1.5 times, Hg by 1.3 times, and Cu by 1.14 times in zone 2 (Privolzhsky district).The results are of interest for further analysis and identification of interrelations in the territory of the Republic of Tatarstan, Russia, where exposure levels may vary between regions or separate subgroups living in the same territory. CONCLUSION: Research in the field of biomonitoring in Kazan established the levels of exposure to toxic elements among the studied population and provided means for comparing exposure for further research by population groups by age, sex, and ethnicity. Moreover, biomonitoring results can be used to determine research priorities, measure exposure trends over time, and verify effectiveness of individual measures to combat pollution and other measures in the field of the environment and public health. The study presents modern technologies for assessing exposure to chemical pollutants using human biomonitoring methods and demonstrates its advantages.

An overview of preconcentration techniques combined with inductively coupled plasma mass spectrometry for trace element determination in biological studies.

In the last decades, the determination of trace elements in biological materials has emerged as an important area of study because of its relevance to human health and the environment. Inductively coupled plasma mass spectrometry (ICP-MS) has proven to be a powerful tool for trace element analysis, owing to its high sensitivity and ability to determine several elements in a single measurement. However, given the complex nature of biological matrices and the presence of elements, most of them at ultratrace levels, it becomes crucial to complement ICP-MS with preconcentration techniques to increase the sensitivity and selectivity of analytical methods. This article presents an exhaustive overview of liquid- and solid-phase preconcentration techniques used in combination with ICP-MS for trace element determination in different biological samples from 2000 to the present. An in-depth discussion of the advances on the application of state-of-the-art solvents and materials in trace element extraction and preconcentration is presented. Special attention is given to different strategies for elemental speciation analysis, employing both chromatographic and non-chromatographic techniques. The role of automation in these methodologies is also described. Finally, future trends and challenges related to this topic are discussed.

The Biological Monitoring as a Source of Information on Environmental Pollution with Heavy Metals

Abstract The influence of environmental pollution on living organisms has been known for a long time, but it was not until the second half of the twentieth century that methodical studies on the influence of anthropopressure on changes in ecosystems began. Living organisms began to be used as biological indicators of environmental pollution. Cyclical and quantitative studies of pollutant concentrations in bioaccumulators have become the basis of modern biological monitoring (biomonitoring) of environmental pollution. Biomonitoring studies are carried out with the passive method (passive biomonitoring), in which living organisms occurring in their natural environment are analysed, and with active methods (active biomonitoring), in which, for example, plants living in the environment with low pollution are transferred and displayed in more polluted ecosystems e.g. heavy metals. The analysis of trace elements, including heavy metals accumulated in algae, mosses and lichens used in biological monitoring provides a lot of information on, among others concentration and origin of pollutants and the directions of their spread. Biomonitoring is used to assess the level of contamination of selected ecosystems, as well as the impact of individual emitters on the environment. An important element in determining the concentrations of trace elements in biological material used in biomonitoring is the proper planning of the experiment, taking into account, among others: methods of collecting or exposing samples, selection of analytical methods and methods of evaluation and interpretation of results. The aim of the presented long-term research, conducted by the Research Team of the Institute of Biology of the University of Opole, was to show that analytical techniques using biota samples can provide reliable data on the past, present and future state of the environment. However, it should be remembered that in order for the results of biomonitoring studies to be reliable and comparable, the applied research methodologies should be consistent and repeatable. In the presented research, Palmaria palmata and Spirogyra sp. algae, Pleurozium schreberi mosses, Hypogymnia physodes and bark of deciduous trees were used. In samples of biological material by the method of atomic absorption spectrometry, the concentrations of heavy metals, including Ni, Cu, Zn, Cd and Pb, were determined. On the basis of the conducted research, it was unequivocally stated that the biomonitoring methods are a good complement to the classic methods of environmental quality assessment. The analysis of the elements accumulated in the biological material provides us with information about the quality of the examined ecosystems, the introduced pollutants and their potential sources. This information allows for the introduction of effective measures to improve the quality of the environment.

Monitoring of indicators of mineral metabolism in new zealand white rabbits

The quality of livestock products depends on the mineral status of the animals. The study of mineral elements makes it possible to investigate changes in the environment and to prevent negative impacts both on the animal organism, the wellbeing of which is completely dependent on humans, and on the human organism, as the final consumer of food of animal origin. A promising direction in veterinary medicine is the development of new methods of non-invasive diagnostics for assessing the state of health and determining metabolic disorders of essential elements in the body of rabbits, because these methods will be more humane and will facilitate the work of a veterinary medicine doctor. The aim of the study was to determine the characteristics of mineral metabolism in rabbits of the New Zealand white breed by age and sex and the informativeness of the assessment of metabolism for the use of various biological materials. The studies were carried out under production conditions on 24 clinically healthy rabbits of the New Zealand White breed, of all ages and sex. For research, blood, urine, and hair were taken from the animals. The content of trace elements in biological materials was determined by the method of atomic emission spectrometry with inductively coupled plasma. A significant correlation was revealed between the content in the blood plasma of rabbits of Calcium with hair (-0.42), Manganese with hair (-0.32), Iron with hair (0.63), Zinc with hair (0.40), Copper with hair (0.39) and with urine (0.44); between the content in whole blood of rabbits of Calcium with hair (0.47) and with urine (- 0.33), Manganese with hair (-0.32); between the content of Cobalt with hair in the urine (-0.35). The dynamics of the content of Calcium, Manganese, Iron, Zinc, Cobalt, and Copper in the biological materials of rabbits depending on their age and sex was found out, which is indicated by a significant increase in the blood plasma of Calcium, Manganese, Iron, Zinc, Cobalt, and Copper in females from 70 to 240 days and a significant increase in Manganese and Zinc and a decrease in Copper in males from 70 to 90 days. The informational content of the non-invasive method for diagnosing microelementoses in rabbits has been experimentally and theoretically substantiated, and the informational content of the microelement composition of hair for biogeocoenotic diagnostics has been proved, which is appropriate for medical examination and mass research of rabbits. In the future, we plan to investigate other elements in different biological materials of rabbits, followed by an assessment of the information content of noninvasive methods for diagnosing disorders of mineral metabolism.

Elemental plasma content and urinary excretion in vineyard farmers occupationally exposed to pesticides in southern Brazil.

This is a cross-sectional study with data and biological material collection from vineyard farmers in southern Brazil. An interview was carried out through a questionnaire developed according to the reference guide of the state government. Plasma and urine samples were screened for Aluminum, Chromium, Manganese, Copper, Nickel, Cobalt, Zinc, Arsenic, Selenium, Cadmium, Antimony, Barium, Mercury, Lead and Uranium, with a technique for fast determination of these elemental contents in biological material utilizing dynamic reaction cell inductively coupled mass spectrometry. Principal component analysis was used to identify associations between these elemental contents in biological samples and the information obtained from the interviews. The farmers showed some trace elements in plasma and urine at a higher concentration than unexposed populations from other studies. This study highlights recent findings of trace elements in biological material and their association with characteristics of pesticide use. In addition, it also contributes to the gap in the literature regarding trace elements content in plasma and urine of workers exposed to pesticides.

Development of interface for online coupling of micro-fluidic chip-based photo-micro-reactor/ultrasonic nebulization with microwave induced plasma spectrometry and its application in simultaneous determination of inorganic trace elements in biological materials

A novel analysis online system based on direct coupling of micro-fluidic μchip-based photo-micro-reactor/ultrasonic nebulization (μchip-UV/MR/USN) to microwave induced plasma-optical emission spectrometry (MIP OES) for simultaneous determination of inorganic trace elements in human body fluids and water samples was developed. A univariate approach and the simplex optimization procedure were used to achieve optimized conditions and derive analytical figures of merit. Minimum dead volume, high photo-decomposition and nebulization efficiency and high sample transport efficiency were obtained by using this interface. The experimental concentration detection limits for simultaneous determination, calculated as the concentration giving a signal equal to three times the standard deviation of the blank (LOD, 3σblank criterion, peak height) were 30, 6, 1, 2, 10, 2, 7, 5, 8, 10, 9 and 30μgL−1 for Ba, Ca, Cd, Cu, Fe, Li, Mg, Mn, Pb, Sr, Zn and C, respectively. Repeatability expressed as the relative standard deviations (RSD, n=6) for the target elements ranged from 4% to 8%. Quantitative data obtained for Seronorm urine and water reference materials were in good agreement with the corresponding reference values, proving the potential of this analysis system for multi-element trace analysis via MIP OES. The proposed method had been successfully applied for the determination of inorganic trace elements in urine, mineral water and implant fluid samples. The developed method is quite suitable for routine analysis of inorganic trace elements in biological and environmental fields and precious biological samples such as implant fluids.

High resolution SIMS analysis of arsenic in rice

Determining the distribution of trace elements in biological materials with subcellular resolution is very challenging but vitally important in order to understand their mechanisms of uptake. Rice grain is efficient in the accumulation of arsenic (As) in the grain, potentially posing a severe health risk to millions of people in South‐East Asia. The NanoSIMS is a state‐of‐the‐art microscope capable of high resolution chemical imaging (down to 50 nm) and detecting very low elemental concentrations (parts‐per‐million levels). This makes it ideally suited for trace element localisation in biological materials. This paper shows how the NanoSIMS can be used to investigate the localisation of As in rice grain at high resolution and how different treatments result in different distributions in the grain. The precise location of parts‐per‐million As concentrations and its localisation with other elements at the subcellular scale in rice roots are also shown. Copyright © 2012 John Wiley & Sons, Ltd.

Laser-induced plasma for detecting trace elements in biological materials

Laser-induced plasma for detecting trace elements in biological materials

The use of a portable total reflection X-ray fluorescence spectrometer for trace element determination in freshwater microcrustaceans ( Daphnia)

The suitability of a newly developed, portable total reflection X-ray fluorescence (TXRF) spectrometer (PicoTAX, Roentec, Berlin, Germany) to analyze trace elements in biological material was tested and compared with a stationary instrument (Spectrometer 8030 C, FEI, Munich, Germany). For that, single freshwater microcrustacean specimens (Daphnia spec.) with dry weights ranging between 1.6 and 18.8 μg individual −1 were prepared according to the dry method and analyzed with both instruments. Additionally, for orientation purposes, freshly collected Daphnia were prepared in field according to the wet method directly on the glass carrier and analyzed using the portable PicoTAX. For method validation, certified reference material (CRM 414, plankton) was analyzed. The results of the in-field measurements demonstrate that the PicoTAX yields very fast and sufficiently sensitive in-field measurements on the element content of minute biological samples. For As, Cu, K, Mn, Ni and Sr, a good correlation was found between the two spectrometers. Only for Ca, Fe, Pb and Zn the comparison with the results of the stationary equipment has shown significant differences.

Determination of major and trace elements in biological materials by microwave induced plasma optical emission spectrometry (MIP-OES) following tetramethylammonium hydroxide (TMAH) solubilization

A simple, alternative method to acid digestion is presented for the preparation of biological materials for major and trace elements by microwave induced plasma optical emission spectrometry (MIP-OES). Standard reference materials were solubilized using a methanolic solution of tetramethylammonium hydroxide (TMAH) by the application of ultrasonic agitation. Following dilution with water suspensions were pumped to a V-groove Babington-type nebulizer then into argon plasma. Limits of detection and precision are reported for major (Na, K, Ca, Mg) and trace (Cu, Fe, Sr, Zn) elements. Standard addition procedures were used to minimize possible matrix interferences. The method offers relatively good precision (R.S.D. ranged from 6 to 12%). Measured concentrations are in satisfactory agreement with certified values for the biological reference materials: TORT-1 (Lobster hepatopancreas), IAEA-153 (Milk powder) and NIST 1577 (Bovine liver). The simple procedure could be useful as a routine analysis of biological materials.

Determination of trace elements in biological materials using tetramethylammonium hydroxide for sample preparation

A method to prepare milk powder, bovine liver and bovine muscle samples for analysis by electrothermal atomic absorption spectrometry (ETAAS) is proposed. Samples are mixed with a small amount of tetramethylammonium hydroxide (TMAH) and a stable and homogeneous slurry is produced in ca. 2 h with heating at 60–70 °C. After such sample preparation and dilution with water, trace elements are determined in certified reference materials. Pyrolysis and atomisation temperatures are optimised for each element, and several modifiers are investigated. External calibration is used for every analyte. Limits of detection (LODs), precision and accuracy are reported for Cd, Pb, Ni, Cr, Cu and Ag and compared with those obtained after conventional acid digestion. The main advantages of the proposed method are the simplicity of sample preparation and the longer lifetime of the graphite tube.

Atomic-Absorption Spectrometry in the Elemental Analysis of Biological Materials

Atomic-absorption spectroscopy methods are considered for determining trace elements in biological materials, including whole blood, serum, and urine, and also in ectodermal samples (hair and nails). Unified measurements in these analyses require the certification of the latest methods of performing measurements, reference materials for the compositions of biological substances, and the development of specialized instruments for certain elements.

Chiral speciation of trace elements: approaches to the speciation of selenoaminoacid enantiomers in biological samples

The “state of the art” of chiral trace element speciation, that is, the recognition of the particular enantiomer in which the trace element sought is occurring, is given here. The importance of such studies and speciation information is highlighted. Recent advances and trends in the development and applications of analytical approaches for chiral speciation of trace elements in biological material are also reviewed. A comparative overview is given of existing selenoaminoacids chiral speciation methods, based on hybridization of an adequate chiral separation technique (e.g., high-performance liquid chromatography, gas chromatography or capillary electrophoresis) coupled on-line with selenium specific detection by inductively coupled plasma mass spectrometry (ICP-MS). Applications of these hybrid methodologies, reported so far in the literature, to selenoaminoacids chiral speciation in biological real samples are also reviewed.

INAA of Trace Elements in Biological Materials Using the SLOWPOKE-2 Reactor in Jamaica

The biological standard reference materials Orchard Leaves SRM 1571 and Oyster Tissue SRM 1566a was analysed by instrumental neutron activation analysis (INAA) at the International Centre for Environmental and Nuclear Sciences, Jamaica at (ICEN) and at the Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Brazil. The comparison of the results with those obtained with the more powerful reactor are used to evaluate the possibilities of INAA for the analysis of biological samples at ICENS. The detection limits, the precision and accuracy of the results obtained in both laboratories are compared. The advantages and disadvantages of the different irradiation facilities are discussed. Some results obtained for Jamaican biological samples are also presented.

Determination of trace elements in biological materials by ETV-ICP-MS after dissolution or slurry formation with tetramethylammonium hydroxide

A method to prepare biological samples to be analysed by electrothermal vaporization inductively coupled plasma mass spectrometry is proposed. A solution or slurry was formed by mixing a sample aliquot, 20–100 mg, with a small volume, 10–200 µL, of a 25% m/v tetramethylammonium hydroxide solution. For animal tissues, complete dissolution was obtained, whereas for the plant and whole egg materials, slurries were obtained. The slurries were stirred manually, every three readings, in the instrument. The pyrolysis and atomization temperatures were optimized, using Pd as a carrier–modifier for As, Se, Te, Ag, Cr, Cu, V, Ni, Mn, Co and Cd. An Ir-coated tube was used for Pb, Sb, Sn and Bi. External calibration was used preferentialy, but in some instances, the analyte additions method was employed. Good results were obtained for four certified reference materials. However, Cr and Cd could not be determined in the bovine muscle sample owing to spectral interferences and matrix effects, respectively.

Direct Determination of Trace Elements in Biological Materials by Inductively Coupled Plasma Atomic Emission Spectrometry with a Tungsten Boat Furnace.

Sample cuvette - tungsten boat furnace (TBF) - inductively coupled plasma atomic emission spectrometry was investigated for the direct determination of trace amounts of cadmium and lead in biological materials. To each small sample cuvette made by tungsten, the mixture of a ground biological sample and powdered diammonium hydrogenphosphate was accurately weighed. Tetramethylammonium hydroxide solution was injected into it. Then, the cuvette temperature was maintained at a wet-digestion temperature to decompose the solid sample. After the on-furnace digestion was completed, the temperature was succeedingly elevated up to generate the analyte vapor to introduce into the plasma.

A new solid-liquid extraction sampling technique for direct determination of trace elements in biological materials by graphite furnace atomic absorption spectrometry

A new solid-liquid extraction sampling technique with graphite furnace atomic absorption spectrometry is based on the quantitative extraction of the element of interest from the biological powdered samples into a liquid phase of 1 mol 1 −1 nitric acid solution. Examinations of the conditions for sample preparation using solid-liquid extraction (i.e. the effect of concentration of nitric acid, sample mass and ultrasonication time on the extraction) have been carried out in order to obtain 100% extraction of cadmium, copper, lead and manganese from powdered biological samples to the liquid phase. 100% of extraction of these metals is successfully carried out using 1 mol 1 −1 nitric acid, and separation of solid phase and liquid phase is done by using a centrifuge (20 min, 4000 rev min −1). The proposed method is applied to the determination of cadmium and lead at 0.1 μ g −1 levels and of copper and manganese at 10 μ g −1 levels in powdered biological samples. These analytical results are ascertained by microwave induced nitrogen plasma-mass spectrometry. Detection limits for cadmium, copper, lead and manganese are, respectively, 0.012 μ g −1, 0.829 μ g −1, 0.082 μ g −1 and 0.125 μ g −1 in solid samples, when 50 mg of powdered biological samples is extracted in 5 ml of 1 mol 1 −1 nitric acid and then 10 μ l of extracted solution is measured. Precisions of the determination (relative standard deviation at five determinations) of cadmium, copper, lead and manganese are 3.4%, 3.1%, 3.9% and 3.1%, respectively.

Preconcentration of trace elements in biological materials by dry ashing for TTPIXE analysis A study of matrix effects

Trace elements in biological materials were preconcentrated by dry ashing at 550°C in order to improve the detection limits for thick-target PIXE analyses. The analytical procedure was calibrated with equally prepared ashes of certified biological standard reference materials (SRMs). The matrix effects were studied both theoretically and experimentally. A drawback of the ashing procedure is that volatile elements such as halogenides and sulfur can be partly lost depending on the composition of the material studied. Thick-target PIXE combined with dry ashing is a sensitive and reliable technique for the determination of elements with atomic number > 20 in biological materials with a low ash content.

Neutron activation analysis for the determination of trace elements in biological materials.

Neutron activation analysis, in both its radiochemical and instrumental forms, is a precious technique for the determination of trace elements in biological materials. Probably its most important advantage is its relative freedom from errors resulting from contamination of the samples. Invaluable characteristics are also its excellent sensitivity, outstanding selectivity, and remarkable multielement capability. It is, however, necessary to warn against uncritical expectations. This is best illustrated by the seriously inconsistent results obtained in several laboratories. Because of the necessity to have access to a nuclear research reactor, the stringent safety rules to be observed, the rather high costs of the analyses, the relatively low sample throughput, and the sometimes long delay between the taking of a sample and the obtaining the final result, the use of neutron activation analysis remained restricted to a few--essentially research--laboratories. It found its main application in solving arduous problems and in paving the way for other analytical techniques better suited to routine applications.

Validation of the cumulative or replicate NAA method for the determination of trace elements in biological materials.

To make the best use of time and facilities, a neutron activation system, fully automatic, including spectrum and data processing, to be used with short-lived nuclides, has been recently developed at the Portuguese Research Reactor (in Portuguese "Reactor Portugês de Investigação," RPI). Using this system, the cumulative neutron activation analysis method is now being implemented. This article summarizes the experimental procedures used to validate the cumulative NAA method for the determination of selenium in biological samples, emphasizing the determination of the essential characteristics of precision, accuracy, and limits of detection and of quantification of the method. The article also examines how detection limits and precision are improved when the samples are analyzed by this method compared to the cyclic activation measurements in use at RPI for the determination of selenium. The improvement is demonstrated for the measurement of selenium in several reference materials when the result obtained by adding up seven spectra of separate aliquots of the same sample is compared to the result from a cumulative spectrum of seven (whenever possible) consecutive cycles of a single sample.