Use of different physical separation techniques for trace element speciation studies in natural waters (original) (raw)
Related papers
Environmental Chemistry, 2015
Environmental context Trace elements are ubiquitous in natural waters where their levels are highly variable depending on natural factors and anthropogenic pollution. The chemical form of the element determines its behaviour in the environment and whether it is likely to pose a risk to environmental and human health. This paper focuses on elemental forms in freshwater systems: it reviews analytical methods, gathers available data, and assesses trends, needs and open issues in this field. Research in voltammetric speciation methods has been mainly driven by the research interests of the oceanographic scientific community and methods were subsequently adapted to freshwater conditions. Nonetheless, different processes, variability of geological, chemical, biological and ecological settings on the one side, and different human land and water uses on the other imply specific needs and a strong shift in concerns for inland waters in terms of investigated analytes. This review paper focuse...
Elemental Speciation Analysis in Environmental Studies: Latest Trends and Ecological Impact
International Journal of Environmental Research and Public Health
Speciation analysis is a key aspect of modern analytical chemistry, as the toxicity, environmental mobility, and bioavailability of elemental analytes are known to depend strongly on an element’s chemical species. Henceforth, great efforts have been made in recent years to develop methods that allow not only the determination of elements as a whole, but also each of its separate species. Environmental analytical chemistry has not ignored this trend, and this review aims to summarize the latest methods and techniques developed with this purpose. From the perspective of each relevant element and highlighting the importance of their speciation analysis, different sample treatment methods are introduced and described, with the spotlight on the use of modern nanomaterials and novel solvents in solid phase and liquid-liquid microextractions. In addition, an in-depth discussion of instrumental techniques aimed both at the separation and quantification of metal and metalloid species is pres...
Chemical Speciation of Heavy Metals in Ground and Surface Waters
The 2008 Annual Meeting, 2008
Metal speciation in natural waters is of increasing interest and importance because of toxicity, bioavailability, and environmental mobility. Biogeochemical behavior and potential risk in general are strongly dependent on the chemical species of metals. The present study aims to determine the distribution of chemical species of dissolved heavy metals in shallow and deep aquifers and surface waters from Buddha nala stream and Sutlej River of Punjab, north-west India. Attempt was also made to identify different possible minerals that may control the solubility of elements in these aqueous solutions. The study was performed at village Walipur in Ludhiana ( 30 0 55 / N, 75 0 54 / E) district of Punjab, north-west India, where Buddha nala surface water stream loaded with heavy metals from municipal waste and Industrial effluents contaminate underground water. A sutlej River also flowed a couple of Km from the village site. Ground water samples were collected at four different occasions from the same sites of shallow aquifer (45 feet deep) and deep aquifer (200 feet deep) by the already installed hand pump and tube well adjacent to Buddha nala stream. Before sampling the water was drawn for half an hour to empty the hand pump and tube well pipes in order to collect the fresh water from the shallow and deep aquifers, respectively. Surface water samples on four different occasions were also taken from Buddha nala stream and Sutlej River. Polyethylene bottles of 50 ml volumes were used for collection of water samples. These bottles were repeatedly washed with the water to be sampled. Bottles were fully filled with water and closed avoiding air bubbles. Field measurements of redox potential (Eh) were also made at the time of water sampling. The redox meter checked with Zobell's solution several times during the investigation period. Water samples were taken from each location and brought back to Laboratory at Punjab Agricultural University for further analyses. The samples were put in a cooled ice box during transportation and stored in refrigerator until analysis (at 5 0 C). The pH of water samples was determined using Elico model L 110 glass electrode in combination with calomel as reference electrode on pH meter. The electrical conductivity of water samples was measured by Elico model CM-84 Conductivity Bridge. The carbonates and bicarbonates concentrations were measured by titration a known volume of water against standard sulfuric acid using phenolphthalein and methyl red as indicators respectively. The chloride concentration in water samples were measured by titrating with a known volume against standard N/40 silver nitrate solution using potassium chromate as indicator. All samples were filtered and acidified prior to analysis. The acidified water samples were analyzed for Cadmium, Nickel, Lead, Zinc, copper, Iron, Manganese and sulfur on Inductively Coupled Argon Plasma of Thermo Electron corporation iCAP 6000 series. Mean of Metals and dominant anions composition of waters determined after four occasions for different sites are listed in . The higher concentration of Cd, Cu,Fe, Mn, Ni, and Pb in waste water of Buddha nala stream must be due to disposal of Industrial effluents. The ionic strength of waste water was also three times more than other water sources. Comparatively high concentration of Zinc (16.10 uM) was measured in water of shallow aquifer than water of deep aquifer and surface water of Buddha nala stream and Sutlej River. The geochemical speciation model Visual MINTEQA2 Version 3.11 was used to calculate the equilibrium concentrations of dissolved species for four solutions, representing the range of water compositions encountered in the shallow and deep aquifers as well as in surface waters of Buddha nala
Determination of Trace Elements Bound to Soils and Sediment Fractions
2000
Abstract: This paper presents an overview,of methods,for chemical speciation analysis of elements,in samples,of sediments,and soils. The sequential leaching procedure is thoroughly discussed, and examples of different applications are shown. Despite some drawbacks, the sequential extraction method can provide a valuable tool to distinguish among,trace element fractions of different solubility related to mineralogicalphases. The understanding of the speciation of trace ele-
Speciation and Bioavailability of Trace Metals in Water: Progress Since 1982
Australian Journal of Chemistry, 2004
The advances in studies of trace metal speciation and bioavailability since Mark Florence’s 1982 review of the topic, published in Talanta, have been comprehensively reviewed. While the relative merits of kinetic and equilibrium approaches are still being determined, advances in the applications of stripping voltammetry, including the application of microelectrodes and an appreciation of detection windows in both CSV and ASV, have been matched by the introduction of new dynamic techniques including diffusive gradients in thin films (DGTs), permeation liquid membranes (PLMs), and improved applications of chelating resins. There have also been improvements in equilibrium techniques such as ion-selective electrodes and Donnan dialysis. The ability of geochemical speciation models to predict metal complexation by natural organic matter has greatly improved, yet the models still require validation against field measurements. More reliable and relevant bioassays have been developed using ...