Lecture 6Sample preparation

Component Percent

Water ~92

Proteins 6–8

Salts 0.8

Lipids 0.6

Glucose (blood sugar)

0.1

Composition of blood plasma

Blood serum is blood plasma without fibrinogen or the other clotting factors (i.e., whole blood minus both the cells and the clotting factors)

Blood Samples:Blood: arterial

capillaryvenous

Blood Samples:

Anticoagulants: lithium heparinsodium heparinNaF sodium citrateEDTA

Serum: no anticoagulant

Plasma: centrifugation with anticoagulant present

Blood cells: erythrocytes

Urine 20-50 mL

Stomach content 25 -50 mL

Tissue Hair, nails 2-5 g if possible

Many of options in postmortem work

Sampling

LiquidOptional protein precipitation

SolidOptional protein precipitation

Homogenize in buffer

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

DATA COLLECTION

Data processing and interpretation

Organic Compounds

Air/gas sampling

canistersbags

Cleaned Polyurethane Foam (PUF) Cartridges and Resins

Solid Phase Extraction cartridges

Headspace vial

Caps & septa

Microdiffusion (Conway) cell

Preconcentration of volatile compounds

A simple device for headspace LPME. Stirring and thermostating are optional.

A 1 mL drop at the end of a syringe needle.

Liqiud phase microextraction (LPME)

SPME

Solvent extraction techniques

Filters:Can be also used for Solid Phase Extraction

Solid Phase Extraction

Inside the SPE cartridge…

Various sorption techniques:

centrifuge

positive pressure

Large volumes:

SPE extraction:Lots of junk removed!