Nephelometry: Principles and Applications

What is Nephelometry?

• A laboratory technique used to measure the concentration of suspended particles in a fluid
• Based on the principle of light scattering by particles

Principles of Nephelometry

• When light is shone through a fluid containing particles, the particles scatter the light
• The scattered light is detected by a sensor, which measures its intensity
• The intensity of scattered light is directly proportional to the concentration of particles

Applications of Nephelometry

• Measurement of protein concentrations in biological fluids (e.g., urine, serum)
• Detection of bacterial contamination in water and food samples
• Monitoring of particle concentrations in pharmaceuticals and cosmetics
• Research applications in fields like immunology, microbiology, and biochemistry

Types of Nephelometry

• Forward scatter nephelometry: measures scattered light at a small angle (e.g., 10-20°)
• Right-angle nephelometry: measures scattered light at a 90° angle
• Backscatter nephelometry: measures scattered light at a large angle (e.g., 150-170°)

Advantages of Nephelometry

• High sensitivity and accuracy
• Rapid results (typically within minutes)
• Non-invasive and non-destructive
• Simple and relatively inexpensive equipment

Limitations of Nephelometry

• Interference from other substances in the fluid can affect accuracy
• Calibration required for each specific application
• May not be suitable for highly concentrated or highly absorbing samples