A L O S Project Workshop IV. S OLID- P HASE E XTRACTION. ALOS: ROSKILDE-MEETING November 2005. Outline. Principles of solid phase extraction Features and benefits Silica products and polymers Practice Applications. ALOS: ROSKILDE-MEETING November 2005. Principles
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ALOS: ROSKILDE-MEETING November 2005 Outline • Principles of solid phase extraction • Features and benefits • Silica products and polymers • Practice • Applications
ALOS: ROSKILDE-MEETING November 2005 • Principles • Why do sample preparation? • Remove interferences from sample • More accurate results • Concentrating analytes to improve detection • Protecting equipment to reduced costs
ALOS: ROSKILDE-MEETING November 2005 Principles of SPE SPE is an extraction process whereby an aqueous sample is filteredthrough a thin bed of sorbent particles, the analytes of interest are removed from the liquid matrix, and concentrated onto the sorbent. Once concentrated, the analytes are removed by an eluting solvent.
ALOS: ROSKILDE-MEETING November 2005 Comparison of LLE vs SPE Disk LLE • Uses 200 - 500 ml solvent • Shaking / continuous process • Forms emulsions • Little selectivity • Takes 1 - 2 hours / sample SPE disk • Uses 2 - 20 ml solvent • Filtration process • No emulsions formed • Wide selectivity (adsorbent) • Takes 10 - 20 min. / sample
ALOS: ROSKILDE-MEETING November 2005 Problems with the LLE Procedure • Tedious and time-consuming • Shaking and separation time • Evaporation time • Expensive-labor and materials • Time factor • Solvent cost and exposure • Solvent disposal • Poor results • Forming of emulsions • Irreproducible extractions • Low recoveries
ALOS: ROSKILDE-MEETING November 2005 What are the Benefits of SPE? • SPE uses less solvent than LLE • SPE is faster (at least 5 times) • High capacity • Total SPE costs are considerably less than LLE • High selectivity: broad choice of bonded phases and solvents • Automation much easier
ALOS: ROSKILDE-MEETING November 2005 Conditioning of silica-based sorbents Add an organic solvent to rinse and activate the alkyl-chains (C18, C8 etc.)! Don´t let the column run dry during conditioning!
ALOS: ROSKILDE-MEETING November 2005 Experiment 1: Rapid Extraction of natural dyes in beverages Sample Preparation: 1 mL blackberry-juice is dissolved in 2 mL of distilled water. Column Conditioning: A 3 mL C18 (Baker: 7020-03) SPE cartridge is conditioned with 1 mL methanol followed by one column volume of distilled water. Sample Addition/Wash: The prepared sample is aspirated through the column. A 5 mL distilled water wash is used to remove sugars, sugar colouring and organic acids. Elution: The dye(s) [anthocyanines, flavonoids, tannins and/or alkaloids)] is (are) eluted with a column volume of methanol. Sometimes propanol-2 will be more successful. Analysis: For detailed analysis- an absorption spectrum can be taken from the eluate. - TLC-experiments can be done.
ALOS: ROSKILDE-MEETING November 2005 • Environmental • - PAH ‘s from water and soil • - PCB‘s from oil- • - Pesticides from water/soil- • - etc. • Food/Feed/Beverages • - Aflatoxine from corn meal • - Caffeine from di-caffeinated diet cola • - Vitamin E from juice • - etc. • Pharmaceutical/Clinical/Biological • - Benzodiazipines from serum • - Anabolic Steroids/Urine • - Aflatoxine from liver • - etc.
ALOS: ROSKILDE-MEETING November 2005 Experiment 1: Rapid Extraction of natural dyes in beverages Sample Preparation: 1 mL blackberry-juice is dissolved in 2 mL of distilled water. Column Conditioning: A 3 mL C18 (Baker: 7020-03) SPE cartridge is conditioned with 1 mL methanol followed by one column volume of distilled water. Sample Addition/Wash: The prepared sample is aspirated through the column. A 5 mL distilled water wash is used to remove sugars, sugar colouring and organic acids. Elution: The dye(s) [anthocyanines, flavonoids, tannins and/or alkaloids)] is (are) eluted with a column volume of methanol. Sometimes propanol-2 will be more successful. Analysis: For detailed analysis- an absorption spectrum can be taken from the eluate. - TLC-experiments can be done.
ALOS: ROSKILDE-MEETING November 2005 Experiment 2: Rapid Extraction of iron-ions from water samples or waste water Sample Preparation: Dissolve 100 mg Fe(NO3)3 or FeCl3 in 10 mL of distilled water or use an amount of approximately 100mL waste water, which contains iron (III) ions. Column Conditioning: A 3 mL sulfonic acid (Baker: 7090-03) SPE column is conditioned with 2 mL methanol followed by one column volume of distilled water. Sample Addition/Wash: 2 mL of the sample is aspirated through the column. The column is washed with 2 mL of distilled water. Elution: Fe3+ -ions are eluted in 1-2 mL hydrochlorid acid (c=0,1 M). The eluate is coloured yellow. Analysis: For detailed analysis - add NH4SCN to the eluate. The colour changes to deep red.
ALOS: ROSKILDE-MEETING November 2005 Experiment 3: Rapid Extraction of sugars (glucose) Sample Preparation: Dissolve 100 mg glucose in 10 mL water. Column Conditioning: A 3 mL Amino (Baker: 7088-03) SPE column is conditioned with 2 mL ethanol. Sample Addition/Wash: 2 mL of the prepared sample is aspirated through the column. Elution: Sugar is eluted with 2 mL water. Analysis: For detailed analysis - use few drops of Fehling-solutions. For detailed analysis - an absorption spectrum can be taken from the eluate. - TLC-experiments can be done.
ALOS: ROSKILDE-MEETING November 2005 Experiment 4: Rapid Extraction of ß-carotine from Multivitamine-juice or carot-juice Sample Preparation: 5 mL of Multivitamine-juice or carot-juice is filtered or centrifuged. Column Conditioning: A 3 mL C18 (Baker: 7020-03) SPE cartridge is conditioned with methanol followed by one column volume of distilled water. Sample Addition/Wash: The prepared sample is aspirated through the column. A 2 mL distilled water wash is used to remove all the other compounds. Elution: ß-carotine is eluted with about 2 mL heptane-acetone mixture (8:2,v,v). the eluate is coloured yellow. Analysis: For detailed analysis - an absorption spectrum can be taken from the eluate. - TLC-experiments can be performed.
