Determination Of Trace Metal Contents Research Articles

Effect of Agricultural Inputs on the Water-soil Couple in Cocoa-growing Area in the Department of Soubré, Southwestern of Côte d’Ivoire

Background: The cocoa crisis in the 1970s decade in Côte d’Ivoire was manifested by the proliferation of crops pests, reduced production and decreased rainfall. To cope with all these constraints, the producers adopted various strategies, including the use of agricultural inputs to improve the production. Thus, this study aimed to characterize the effects of these inputs on water-soil couple. Methods: First, 12 soil and surface water samples were taken for analysis. Second, determination of trace metal content was done using an atomic absorption spectrophotometer (AAS). Also chemical elements were analyzed using a HACH DR 6000 spectrophotometer. Results: Soil concentrations of exchangeable base Ca2+, K+ and Mg2+ are low with average values of 5.71 cmol/kg, 0.35 and 1.66 cmol/kg, respectively. The soils of cocoa orchards are quite rich in assimilable phosphorus (P). The average phosphorus content is 24.31 cmol/kg with a minimum of 3.92 cmol/kg and a maximum of 78.4 cmol/kg. The study of surface water quality showed that the average values of biochemical oxygen demand for 5 days (BOD5) (18.64 mg/L) and chemical oxygen demand (COD) (15.49 mg/L) are lower than the respective standards of 25 and 125 mg/L of the world health organization (WHO) standard. These surface waters have average concentrations of 0.015 mg/L for cadmium (Cd), 0.042 mg/L for zinc (Zn) and 0.062 mg/L for manganese (Mn), below the respective standards of 0.003, 3 and 0.4 mg/L. Conclusion: This study shows that surface waters are not yet very polluted by these inputs.

Comparison of microwave, dry and wet digestion procedures for the determination of trace metal contents in spice samples produced in Turkey

The concentrations of trace metals (Pb, Cd, Cr, Ni, Fe, Cu, Mn and Zn) in spice samples from Turkey were determined because similar studies have not been published. The experiments were carried out using atomic absorption spectrometry after dry ashing, wet ashing and microwave digestion methods. The study of sample preparation procedures showed that the microwave method was the best. The proposed method showed satisfactory recovery, detection limits and standard deviation for trace metal determination in spice samples. The concentrations of Pb, Cd, Cr, Ni, Fe, Cu, Mn and Zn in the samples were in the range of 0.47-1.89, 0.10-0.93, 0.67-7.15, 0.65-8.69, 88.9-376.3, 4.1-28.7, 11.9-211.3 and 7.84-47.6 μg/g, respectively. Correlations between metal concentrations were evaluated.

Comparison of digestion procedures on commercial powdered soup samples for the determination of trace metal contents by atomic absorption spectrometry

The concentrations of copper, manganese, zinc, iron and aluminum in commercial powdered soup samples produced in Turkey were determined using flame and graphite furnace atomic absorption spectrometry. We compared wet, dry and microwave digestion procedures for the digestion of the soup samples. The microwave digestion procedure for the soup samples was demonstrated to be most effective due to its simplicity and quick results. The accuracy of the method was checked against a standard reference material (SRM 8418 Wheat Gluten). Contents of investigated trace metals in soup samples ranged between 0.41 and 4.78 μg/g for copper, 1.29 and 49.4 μg/g for manganese, 1.26 and 22.5 μg/g for zinc, 4.62 and 61.7 μg/g for iron, and 6.86 and 547.7 μg/g for aluminum. The results were compared with values reported in the literature.

Determination of cadmium in lichens by solid sampling graphite furnace atomic absorption spectrometry (SS-GF-AAS).

The determination of trace metal contents directly from a solid sample is a trend in modern atomic spectrometry. The aim of this study was to develop an analytical method for the routine determination of Cd in lichens using solid sampling graphite furnace atomic absorption spectrometry (SS-GF-AAS). For the determination of Cd, the temperature program of the graphite furnace was optimized using a mixed matrix modifier (Pd + Mg (NO3)2 + Triton X-100). The limit of detection and the limit of quantification were 0.9μg/kg and 3μg/kg, respectively. The analytical method for Cd determination in the plant matrix was verified by the analysis of certified reference materials of lichens, seaweed, and rye grass. The developed procedure was applied to the study of Cd distribution in thalli of Usnea antarctica lichen from James Ross Island, Antarctica. The SS-GF-AAS analytical method is particularly suited for use in environmental studies and plant physiology (the microanalysis of anatomical structures).

Determination of trace metal contents of tobacco in different brands of cigarettes – a valuable tool in forensic investigation and criminology

Determination of trace metal contents of tobacco in different brands of cigarettes – a valuable tool in forensic investigation and criminology

Closed-vessel miniaturised microwave-assisted EDTA extraction to determine trace metals in plant materials

The demonstration of an innovative miniaturised closed-vessel microwave-assisted extraction (µMAE) method under the use of EDTA (µMAE-EDTA) for determination of trace metal contents in grassland (Lolio-Cynosuretum) was examined by ICP-OES. The evaluation of the method was done by comparison of the results with another miniaturised closed-vessel microwave HNO3 method (µMAE-H) and with a macro-scale microwave procedure (MAE-H). Concerning their homogeneity certified plant reference materials (CRMs) were used for validation of the applicability of µMAE-EDTA procedure. For CRMs and 72 real plant samples, no significant differences were found between µMAE-EDTA and MAE-H in the determination of Cd, Co, Cu, Mn, Ni, Pb, and Zn contents. Recovery rates achieved from µMAE-EDTA for CRMs ranged between 100.0–102.6% for the investigated elements. The key characteristics of µMAE-EDTA for determination of trace metal contents in plant samples are: (i) suitability as a high-throughput procedure; (ii) consumption of minimum volume of extracting agent and minimum amount of sample; and (iii) combination of fast, safe and environmentally friendly extraction procedure.

MICRO-PIXE FOR SINGLE CELL ANALYSIS

The knowledge of the intracellular distribution of biological relevant metals is important to understand their mechanisms of action in cells, either for physiological, toxicological or pathological processes. However, the direct detection of trace metals in single cells is a challenging task that requires sophisticated analytical developments. The combination of micro-PIXE with RBS and STIM (Scanning Transmission Ion Microscopy) allows the quantitative determination of trace metal content within sub-cellular compartments. The application of STIM analysis provides high spatial resolution imaging (< 200 nm) and excellent mass sensitivity (< 0.1 ng). Application of the STIM-PIXE-RBS methodology is absolutely needed when organic mass loss appears during PIXE-RBS irradiation. This combination of STIM-PIXE-RBS provides fully quantitative determination of trace element content, expressed in μg/g, which is a quite unique capability for micro-PIXE compared to other micro-analytical methods such as the electron and synchrotron x-ray fluorescence. Examples of micro-PIXE studies for sub-cellular imaging of trace elements in various fields of interest will be presented: in patho-physiology of trace elements involved in neurodegenerative diseases such as Parkinson's disease, and in toxicology of metals such as cobalt.

Determination of trace metal content of various herbal and fruit teas produced and marketed in Turkey

Determination of trace metal content of various herbal and fruit teas produced and marketed in Turkey

Atomic Absorption Spectrometric Determination of Trace Metal Contents of Mushroom Samples from Tokat, Turkey

Six trace metals (Fe, Cu, Mn, Zn, Pb, Cd) were determined in 12 different mushroom samples collected from polluted and unpolluted locations in Tokat, Turkey using flame and graphite furnace atomic absorption spectrometry after dry ashing, wet ashing and microwave digestion. The study of sample preparation procedures showed that the microwave digestion method was the best. The proposed method showed satisfactory recovery, detection limits and standard deviation for trace metals determination in mushroom samples. The results were in the ppm range 184–7560 (Fe), 12–181 (Cu), 16–122 (Mn), 18–403 (Zn), 0.75–7.77 (Pb), and 0.14–5.50 (Cd).

An Unusual Dehalogenating Peroxidase from the Marine Terebellid Polychaete Amphitrite ornata

The terebellid polychaete Amphitrite ornata produces no detectable volatile halogenated secondary metabolites, but frequently inhabits coastal marine sediments heavily contaminated with anthropogenic or biogenic haloaromatic compounds. This animal contains high levels of two very unusual enzymes, dehalogenating peroxidases. We have purified and partially characterized one of these dehaloperoxidases, DHP I. DHP I is a heme enzyme (Mr = 30,790) composed of two identical subunits (Mr = 15,529) and is very rich in the amino acids aspartic acid (+ asparagine) and glutamic acid (+ glutamine). The enzyme converts trihalogenated phenols, such as 2,4,6-tribromophenol, into dihalogenated quinones. The optimum pH for this reaction is 5.0. DHP I is also active against di- and monohalogenated phenols and will oxidize bromo-, chloro-, and fluorophenols. We have identified similar dehaloperoxidase activities in other infaunal polychaetes, including halometabolite-producing species.

Determination of trace metal content in corn oil by atomic absorption spectroscopy

AbstractAtomic absorption spectrophotometry is used for the determination of Cu, Fe, K, Na, Ni and Zn in industrial refined corn oil. The results of five different analytical techniques are compared. Fair agreement is obtained between the char‐ashing method and the dilution procedure. Char ashing is a sensitive and useful technique, if handled correctly. Dilution, coupled to carbon‐rod atomization, is a reliable method. To eliminate errors, due to sample loss, a proper injection technique is required. Extraction methods suffer from incomplete recoveries, owing to deficient break up of the organometallic com‐pounds in oil