Lecture 6 Sample preparation Blood Samples Blood arterial

Lecture 6 Sample preparation

Blood Samples: Blood: arterial capillary venous Composition of blood plasma Component Percent Water ~92 Proteins 6– 8 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)

Blood Samples: Anticoagulants: lithium heparin sodium heparin Na. F sodium citrate EDTA Serum: no anticoagulant Plasma: centrifugation with anticoagulant present Blood cells: erythrocytes

Urine 20 -50 m. L Stomach content Tissue 25 -50 m. L Hair, nails 2 -5 g if possible Many of options in postmortem work

Organic Compounds Sampling Solid Liquid Optional 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

Air/gas sampling canisters bags Cleaned Polyurethane Foam (PUF) Cartridges and Resins

Solid Phase Extraction cartridges

Headspace vial Caps & septa

Microdiffusion (Conway) cell Preconcentration of volatile compounds

Liqiud phase microextraction (LPME) A simple device for headspace LPME. Stirring and thermostating are optional. A 1 m. L drop at the end of a syringe needle.

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!