Spectroscopy is an analytical technique that involves the study of the interaction between matter and electromagnetic radiation. In simple terms, it measures how atoms, ions, or molecules absorb, emit, or scatter light to provide information about their composition, structure, or concentration.
Principle:
- Different elements and compounds interact with light in unique ways.
- By analyzing the light absorbed, emitted, or scattered, one can identify which elements or compounds are present and in what amount.
Types of Spectroscopy in Inorganic Analysis:
- Atomic Absorption Spectroscopy (AAS):
- Measures light absorbed by free metal atoms.
- Used to determine trace metal ions like iron, copper, and lead.
- Flame Emission Spectroscopy / Flame Photometry:
- Measures light emitted by metal ions in a flame.
- Used for alkali and alkaline earth metals like sodium, potassium, and calcium.
- UV-Visible Spectroscopy:
- Measures light absorbed by colored ions or complexes.
- Useful for determining concentrations of transition metal complexes.
- Infrared (IR) and Raman Spectroscopy:
- Used to study bonding and molecular structure in inorganic compounds.
Applications in Inorganic Analysis:
- Identification of metal ions and some anions.
- Quantitative determination of metal ion concentration.
- Studying the structure of coordination complexes.
- Environmental monitoring for metals in water and soil.
- Industrial and pharmaceutical quality control.
Advantages:
- Highly sensitive and accurate.
- Can detect metals at very low concentrations.
- Provides both qualitative and quantitative information.
Limitations:
- Requires expensive instruments.
- Some techniques are element-specific and may need different lamps or sources.