Sample preparation
Sample preparation - contextSample preparation - motivationPurpose of sample preparationOverview 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 FiltrationBox 11 SorbentsBox 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 AnswerProblems
End of chapter3) Solid phase microextraction (SPME)
Answers:
Which of the desirable goals apply for SPME?
Ideal SPME procedures should...
(1) ...extract a well defined percentage of the target compound out of the sample.
Applies. A SPME fiber does not extract all organics from an environmental sample. Extraction must be highly reproducible.
(2) ...extract close to 100% of the target compound out of the sample.
Does NOT apply.
(3) ...extract the target compound in as little solvent or sorbent as possible.
Applies. The SPME contains only very little adsorbent material. The use of an organic solvent can be avoided completely if the compound is thermally desorbed into the chromatographic system.
(4) ...extract as many compounds out of the sample as possible.
Does NOT apply.
(5) ...be cheap and can be automated.
Applies.
(6) ...be quick and safe.
Applies.
(7) ...cause as little toxic waste as possible.
Applies.
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