Sample preparation

Sample preparation - context
Sample preparation - motivation
Purpose of sample preparation
Overview of preparation methods
     Liquid liquid extraction (LLE)
     Solid phase extraction (SPE)
     Solid phase microextraction (SPME)
     Purge and trap (PT)
     (Accelerated) Solvent extraction ((A)SE)
     Supercritical fluid extraction (SFE)
      Filter Techniques (FT)
Box 10 Filtration
Box 11 Sorbents
Box 12 Preconcentration
Selftest
     1) Polar organic solvent
           Answer
     2) Ideal extraction procedures
           Answer
     3) SPME
           Answer
     4) Extraction efficiency
           Answer
     5) Sorption capacity
           Answer
     6) Use as little of an extraction medium as possible
           Answer
     7) Should soil samples be grinded?
           Answer
     8) Solvent volume
           Answer
     9) Extracting an air sample
           Answer
Problems
End of chapter

9) Extracting an air sampl

 

Question:

One way of extracting an air sample is to fill a bottle with the air, add a little solvent, shake it and proceed with analyzing the solvent extract. Why is this rarely done in practice?

 

Answer:

At best, one could extract 2 L of air by this method. Typical air concentrations of organic pollutants are so low that hundreds of cubic meter of air need to be extracted to get above the detection level.