Determinations of metals (Cd, Zn, Co, Mn, Fe) in water, plankton and fish

Determining the levels of metals such as Cadmium (Cd), Zinc (Zn), Cobalt (Co), Manganese (Mn), and Iron (Fe) in water, plankton, and fish involves various analytical techniques. Here’s an overview of the methods commonly used for metal analysis in these environmental compartments:
1. Water Analysis:
• Atomic Absorption Spectrometry (AAS): A widely used technique for quantifying metal concentrations in water samples. It involves atomizing the sample and measuring the absorption of specific wavelengths of light by the metal atoms.
• Inductively Coupled Plasma Mass Spectrometry (ICP-MS): Offers high sensitivity and multi-element capability for metal analysis. It involves ionizing the sample in a plasma torch and measuring the mass-to-charge ratios of the ions.
• Graphite Furnace Atomic Absorption Spectrometry (GFAAS): Similar to AAS but offers greater sensitivity for trace metal analysis by using a graphite furnace to concentrate the analyte.
• Voltammetry: A electrochemical technique where the current is measured while varying the potential across an electrode. It can be used for selective determination of metals in water samples.
2. Plankton Analysis:
• Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES): Similar to ICP-MS but measures the emission of light rather than mass spectrometry. It is useful for analyzing metal concentrations in plankton samples.
• X-Ray Fluorescence (XRF): Provides non-destructive analysis of elemental composition in solid samples, including plankton. It involves irradiating the sample with X-rays and measuring the characteristic fluorescent X-rays emitted by the elements.
• Digestion Methods: Plankton samples may be digested using acid digestion techniques to extract metals for subsequent analysis by AAS, ICP-MS, or other methods.
3. Fish Analysis:
• Atomic Absorption Spectrometry (AAS) and ICP-MS: Similar to water analysis, these techniques can be used to analyze metal concentrations in fish tissue. Sample preparation may involve digestion of the tissue to release the metals for analysis.
• X-Ray Fluorescence (XRF): Can be used for non-destructive analysis of metal concentrations in fish scales or bones.
• Hydride Generation Atomic Absorption Spectrometry (HG-AAS): A specialized technique for determining trace levels of metals like Cd in fish tissue. It involves converting the metal to a volatile hydride compound for detection.