Sample preparation

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Lecture 6 Sample preparation
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Blood Samples
Blood arterial capillary venous
Composition of blood plasma
Component Percent
Water 92
Proteins 68
Salts 0.8
Lipids 0.6
Glucose (blood sugar) 0.1
Blood serum is blood plasma without fibrinogen or
the other clotting factors (i.e., whole blood
minus both the cells and the clotting factors)
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Blood Samples
Anticoagulants lithium heparin sodium
heparin NaF sodium citrate EDTA
Serum no anticoagulant Plasma centrifugation
with anticoagulant present
Blood cells erythrocytes
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Urine 20-50 mL Stomach content 25 -50
mL Tissue Hair, nails 2-5 g if possible Many
of options in postmortem work
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Organic Compounds
Sampling
Solid Optional protein precipitation Homogenize
in buffer
Liquid Optional protein precipitation

• Isolation
• Single step liquid-liquid extraction
• Multiple step liquid-liquid extraction
• Solid phase extraction
• (pre)concentration

DATA COLLECTION
Data processing and interpretation
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Air/gas sampling
canisters
bags
Cleaned Polyurethane Foam (PUF) Cartridges and
Resins
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Solid Phase Extraction cartridges
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Headspace vial
Caps septa
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Microdiffusion (Conway) cell
Preconcentration of volatile compounds
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Liqiud phase microextraction (LPME)
A 1 mL drop at the end of a syringe needle.
A simple device for headspace LPME. Stirring
and thermostating are optional.
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SPME
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Solvent extraction techniques
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Filters Can be also used for Solid Phase
Extraction
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Solid Phase Extraction
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Inside the SPE cartridge
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Various sorption techniques centrifuge positive
pressure
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Large volumes
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SPE extraction Lots of junk removed!