Seps L1

Simple sugas, oligosaccharides, amino acids, some small proteins and peptides, some vitamins

fats, phospholipids, sterol, vitamins, carotenoids

essential oils, LMW fatty acids, flavor compounds, pesticides

proteins, amino acids, color compounds

• qualitative or quantitative
• quantity range of analyte
• size of sample material
• nature of impurities
• desired level of accuracy
• instrumentation required

• remove interfering impurities
• selective enrichment of analyte
• increased [analyte]
• conversion of analyte into other forms for analysis (derivatization)

• 1. drying
• 2. grinding
• 3. solvent extraction
• 4. separation of extract from residue
• 5. cleanup
• 6. derivatization, concentration, etc.

• remove water which is the main component of food matrices
• lyophilization (freeze drying), oven drying, vacuum oven drying

filtration, centrifugation, membrane separation (molecular sieve)

remove extracted impurities that can potentially interfere with further analysis

• ASE/PSE/PFE
• MAE
• UE
• SPE

• accelerated solvent extraction
• pressurized liquid extraction
• pressurized fluid extraction

microwave-assisted extraction

ultrasonic extraction

solid-phase extraction

thermally labile volatile analytes

minimizes the use of extraction solvent by circulation (continuous process)

can be interference from contaminants from the extraction thimble used, so always need to do a blank extraction prior to actual

• involves the use of pressurized liquids or pressurized fluids for extraction
• elevated temperatures and pressures are used in these techniques
• this allows the extraction solvents to penetrate the sample matrices, thus enhancing solvation of desired solute

super-critical CO2 extraction

• water in sample is heated by microwave
• the expansion of the heated water generated pressure from within the sample
• increased pressure disrupts sample matrix from the inside and allows analyte to escape and to be dissolved in extraction solvent
• requires less solvent compared to conventional extraction methods
• the solvent used may be microwave absorbing or non-microwave absorbing

• analytes suspended or dissolved in a liquid mixture are passed over a sorbent material, which selectively binds the solute of interest
• weakly bound impurities are washed out with a weak solvent and the desired analyte(s) are eluted with a strong solvent
• can be used as primary method or just for cleanup step
• several types of sorbent materials are available, depending on the physicochemical properties of the desired analyte (reversed phase, normal phase, ion exchange, affinity)

• condition the column
• load sample into column, some impurities leave immediately by not attaching to the solid phase
• wash the column, more weakly bound impurities leave
• selectively elute the desired sample, leaving behind the last of the impurities in the column

• membrane filtration techniques use specialized materials to achieve separation of particles or molecules based on their size
• the membrane is selectively permeable which allows preferential transport of matter through its pores