Sampling

1
SAMPLE PREPARATION IS OFTEN REQUIRED TO OBTAIN
USEFUL DATA
Sampling Process
Preservation transport issues
Sample Preparation
Analytical Measurements
2
Potential Sample Preps

• Filtering/grinding (e.g., inhomogeneous)
• Dissolution (e.g., solid sample)
• Concentrating (e.g., drinking water sample)
• Extraction (e.g., organics in soil)
• Removal of interferences (e.g., U in spectra)
• Chemical conversion (e.g., product is more easily
  detected)

3
Dissolution Alternatives

• Acid digestion
• Fusion
• Reflux
• Wet and dry ashing
• Bomb
• Microwave assisted

4
Extraction Alternatives

• Methylene chloride organics from
• Supercritical fluid CO2 (with additives)
• Liquid-liquid CCl4 H2O see Fig. 28-12 for
  continuous
• Solid phase new alternatives that can be
  specific