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     Supercritical Fluid
Extraction, Chromatography
  and Other Applications

What is a Supercritical Fluid ?

When the pressure and temperature of a
 substance is raised above its critical pressure
 and critical temperature (the critical point) the
 substance enters the supercritical state.

A Supercritical Fluid is a substance with both
  gas- and liquid-like properties.
Critical Temperature and Pressure

   The Critical Temperature (Tc) is the
    maximum temperature at which a gas can be
    converted to a liquid by increasing the

   The Critical Pressure (Pc) is the maximum
    pressure at which a liquid can be converted
    to a gas by increasing the temperature.
Phase Diagram of Carbon Dioxide

                      Liquid            Fluid

                                       Critical Point
                                       31.3 oC, 1072 psi

                      Triple Point

 Physical Properties of CO2

Phase         Gas              SCF              Liquid

Density       0.6–2.0 x 10-3   0.2 – 0.9        0.8 – 1.0

viscosity     0.5–3.5 x 10-4   2.0–9.9 x 10-4   0.3–2.4 x 10-2

Diffusivity   0.01 – 1.0       0.5–3.3 x 10-4   0.5–2.0 x 10-5
Advantages of Supercritical Fluids as

    Solvating power related to density
     (at constant T)

    Gas-like mass transport properties

    Facile penetration into porous material
Critical Parameters of Common
                                                                         c (g mL )
                               Tc (°C)              Pc (atm)
      CO2                                31.3                72.9                 0.47
      N2 O                               36.5                72.5                 0.45
      SF2                                45.5                37.1                 0.74
      NH3                             132.5                 112.5                 0.24
      H2 O                               374                   227                0.34
      n-C 4H10                           152                 37.5                 0.23
      n-C 6H12                           197                 33.3                 0.23
      Xe                                 16.6                58.4                 1.10
      CCl 2F2                            112                 40.7                 0.56
      CHF 3                              25.9                46.9                 0.52

Source: “SFE and Its use in Chromatographic Sample Preparation” Ed. S. Westwood. Chapter 1
Advantages of CO2 for SFE

   Low critical parameters
   Inert, Non-toxic, Nonflammable, Non-
   Easily purified (inexpensive)
   Nonpolar: dielectric constant similar to
   Modifiers can be used to increase polarity
Supercritical Fluid Extraction (SFE)

           Basic Theory
SFE System Components

          CO2 Pump        Modifier
                           Pump               sample cell
            pressure)                         in heated
        Liquid Carbon            Restrictor
        (requires a dip                          CO2

                                              Solid or
Advantages of SFE over Solvent

       Faster
           Results in minutes rather than hours
       Selectivity results in cleaner extracts
       Low Critical Parameters
           Handling of thermally labile analytes
       Non-hazardous solvents
       Automated
       Cost per test is lower
       Limited or no solvent removal required
       No solvent disposal costs
The Mechanism of SFE

A Three Step Process

  1. Dissolving/Resolving analyte(s)

  2. Sweeping the analyte(s) from the matrix

  3. Trapping the analyte(s)
SFE Mechanism
                    diffuses matrix,      SC-CO2 +
                 dissolves and resolves   dissolved
High Pressure   analyte from the matrix   analyte to
   Liquid                                  the trap


                           Gaseous   Gaseous
                            CO2       CO2
                                               Trapping Solid
CO2 is changing
from a SF (2 ml/min)                           •High Surface Area
to an expanded gas                             •Adequate Amount
(1 L/min)
                                               Trapping Liquid
•Analyte no longer
soluble                                        •High Surface Tension
•Mechanical movement                           •Analyte is Soluble
of analyte due to the                          •Low Volatility
rapid expansion requires                       •Pressurized
the use of trapping
material                                       •Cryogenically Cooled
SFE - Method Development

   Pressure
       Increase pressure increases density = increase in
        solubilizing power.
   Temperature
       Increase temperature may decreases density = decrease in
        solubilizing power (ie CO2 at 100 bar)
   Extraction Time
       Flow Rate
   Fluid Composition
       Co-solvents/modifiers
       Reactant Additive
   Static vs. Dynamic Extraction
Why Use Modifiers?
Analytes that have polar components require the use of a co-

           Triglycerides                 Phospholipids

         CH2OCOR1                           CH2OCOR1
 R2COOCH                            R2COOCH        O
         CH2OCOR3                           CH2OPOR3
       R 1, 2 & 3 groups are long   R 1 & 2 groups are long chain
          chain hydrocarbons          hydrocarbons (nonpolar),
               (nonpolar)                while R 3 contains
                                    phosphorus and nitrogen and
                                               is polar
Modifiers (Co-solvents) in SFE

Role of Modifiers in SFE
Changes in Solvent Polarity
 Interaction with Matrix

 Interaction with Analyte

Methods of Addition
     Directly into extraction cell (spiking)
     On line modifier addition (uses a second pump)
SFE vs. Traditional Sample Extraction Methods

    SFE can be versatile, selective and faster
    SFE reduces hazardous solvent use and cost
    SFE can produce cleaner, more concentrated
     extracts for post extraction analysis
Analyst’s       Time Allotment

       61%                    Collection 6%
                                  Analysis 6%

Routine and Novel Applications of
         Analytical SFE
SFE for Research
Environmental SFE Applications

• Matrices               • Target Analytes
      Soil                 TPH
      Tissue               PAH
      Clay                 PCBs
      Sandy Loam
                            Pesticides
      Sludge
                            Dibenzofurans
      River Sediment
      Marine Sediment
                            Dioxins
      Fly Ash
      Incinerator Ash
Approved Methods
• US EPA 3560 - TPH in Soil:            Supercritical Fluid Extraction of Total
  Recoverable Petroleum Hydrocarbons
• US EPA 3561 - PAH in Soil:            Supercritical Fluid Extraction of
  Polyaromatic Hydrocarbons
• US EPA 3562 - PCB and OCP:              Supercritical Fluid Extraction of
  Polychlorinated Biphenyls (PCBs) and Organochlorine
• US EPA 3545: Pressurized Fluid Extraction (PFE)
• USDOE STD-3013-99: Determination of Residual Water in Impure
  Plutonium Oxides
• AOAC draft: SFE-GC/MS determination of pesticide residues in
  non-fatty fruits and vegetables
Pharmaceutical/Natural Product
               SFE of Natural Products -- Roger M. Smith
                    LC-GC International, Jan. 1996, 9-15

Catharanthus       German        Magnolia      Tansy
roseus             chamomile     grandiflora

Chamomile          Ginger        Peppermint    Thyme

Clove Oil          Kola nuts     Pimento       Turmeric

Dragon head        Lavender      Poppy seeds   Wheat germ oil

English yew        Lemon grass   Rosemary

Feverfew           Lemon peel    Savory
                                Microbial Natural Products
                                       R. M. Smith, op. cit.

Organism                         Extract
Agaricus species                 Carboxylic and fatty acids

Beuveria nivea                   Cyclosporin

Filamentous fungi                Polyunsaturated fatty acids

Flour, moldy bread, mushrooms    Ergosterol

Moldy bran                       Sterol

Moldy grain                      Aflatoxin
                              Extracts from Biomass
                                R. M. Smith, op. cit.

Microorganism            Extract

Actinomycete species     Mycolutein and luteoreticulin

Actinomycete species     Oligomycin A

Aspergillus fumigatus    Sydowinin B and epoxide

Bipolaris urochloae      Ophiobolin A

Penicillium expansum     Chaetoglobosin A

Penicillium sclerotium   (+)-Sclerotiorin

Streptomyces species     Elaiophylin
                            R. M. Smith, op. cit.

• Extracts typically cleaner than those
  obtained with organic solvents.
• Mild conditions minimize degradation.
• SFE methods are faster than organic solvent
  Extraction of Pharmaceuticals Using Pressurized Carbon
 J. R. Dean, S. Khundker, J. Pharm. & Biomed. Anal, 15 (1997) 875-886

• Recoveries from 81% - 95+%
• CO2 and CO2 with modifiers
• Generally faster than other methods with
  better selectivity for target analytes.
• Preconcentration steps could be eliminated
  in some cases.
• Liquid matrices required immobilization on
  solid support or SPE cartridge.
                                                 Animal Feeds
                          J. R. Dean, S. Khundker, op. cit.
Analyte                            Matrix
Menadione                          Rat chow
Tipradane                          Rodent diet

Hypolipidermic drug                Rat feed

Halogenated aromatic phenoxy       Dog feed/rodent feed
Atovaquone                         Rat feed

Fluconazole                        Animal feed

Propanolol, Tamoxifen, ZM 95527,   Rodent diet
                                   J. R. Dean, S. Khundker, op. cit.
Analyte                                 Matrix
Megesterol Acetate                      Tablet
Felodipine                              Tablet
Benzodiazipines (7)                     Tablet/capsule
Caffeine,vanillin                       Tablet
Vitamin A, E                            Tablet
Retinol palmitate, tocopherol acetate   Ointment
Polymyxin B sulphate                    Cream/Ointment
Acylvoir                                Ointment
Sulfamethazole, trimethoprim            Septra infusion
Triamincinolone                         Dermatological patches

Misoprostol                             Hydroxypropyl methylcellulose
                                                 Biological Matrices
                                    J. R. Dean, S. Khundker, op. cit.
Analyte                                 Matrix
Veterinary drugs (4)                    Pig kidney
Nitrobenzamide residue                  Liver
Codeine, morphine, ethyl morphine       Hair
Ketorolac, flavone                      Plasma
Mebervine alcohol                       Dog plasma
Morphine                                Serum
Beudesonide                             Plasma
Caffeine                                Kola nuts
Taxanes                                 Yew tree needles
Chinese herbal medicines                Plants
Diosgenin                               Tubers of Dioscorea nipponica
Taxol and baccatin III                  Needles of Taxus cuspidata
Zingiber zerumet rhizomes               Plants
Mevinolin and hydroxy acid form         Fermentation broth
Phylloquinone                           Soy protein and infant formula
                  J. R. Dean, S. Khundker, op. cit.

Analyte                 Matrix

Triprolidine,           Aqueous
Steroids (10)           Aqueous

Ibuprofen               Aqueous
                        Natural Materials Studied
                                 M. J. Noh, et. al., op. cit.
Specific Name              Part Used
Lycium chinese             Fruit
Schizandre chinensis       Fruit
Citrus unshiu              Fruit bark
Angelica gigas             Root
Cornus officinalis         Fruit
Cnidium officinale         Rhizome
Ginko biloba               Leaf
Aralia cordata             Root
Evodia officinalis         Fruit
Crataegus pinnatifida      Fruit
Paeonia lactiflora         Root
Leonurus sibricus          All
Sophora japonica           Flower
Artemisia capillaris       All
Platago asiatica           Seed
                             Natural Materials Studied, contd.
                                              M. J. Noh, et. al., op. cit.
Specific Name                         Part Used
Ephedra sinica                        All
Aconitum carmichaeli                  Tuber
Scolopendra subspines                 All
Paeonia suffruticosa                  Root
Pueraria thunbergiana                 Root
Polygala tenuifolia                   Root
Coptis japonica                       Rhizome
Astragalus membranaceus               Root
Eucommia ulmoides                     Stem bark
Bupeuri falcatum                      Root
Acanthopanax sessiliflorum            Bark
Epimedium koreaum                     All
Morus alba                            Root bark
Artium lappa                          Fruit
Spirodela polyrhiza                   All
                         M. J. Noh, et. al., op. cit

• For many materials, SFE yielded extracts with
  higher bioactivity than LSE.
• SFE was found to be more selective than LSE
  for target compounds.
• SFE conditions could be optimized to produce
  maximum levels of bioactivity.
                                        Drug Residues
          Analyte              Matrix                  Reference

Sulfamethazine         Swine Muscle Tissue      Cross,

Anabolic Steriods      Bovine Tissue (Muscle Houpalahti and Henion
                       and Liver)
Opiates                Hair, blood and tissue   Multiple Authors

Temazepam              Whole Blood              Scott and Oliver

Cocaine,               Hair                     Brewer,
codeine and morphine
                         Study Summary

• Compared to a conventional SPE method,
  the SFE method was more efficient and
  gave cleaner extracts with recoveries above
• K.S. Scott, J.S. Oliver, J. Anal.Toxicol. 21
  (1997) 297.
Supercritical Fluid Chromatography

• SFC is a separation technique similar to
  HPLC and GC where the mobile phase or
  carrier gas is replaced by a supercritical
  Limitations of GC and HPLC

GC Sample Limitations :
  Thermal stability
  Low molecular weight

HPLC Analytical Limitations :
  No universal detector
  Low efficiency
  Low resolution
Overcomes Limitations of GC and HPLC

•   Extends molecular weight range of GC
•   Lower operating temperature than GC
•   Faster separation time than HPLC
•   Higher separation efficiency than HPLC
•   Universal detector can be used, FID
•   Both packed (HPLC-type) and GC-type
    columns can be used
         Carbon Dioxide, CO2
has desirable properties as a SFC solvent

 • Inexpensive
 • Highly pure
 • Very low UV absorbance
 • NO FID background noise
 • Low critical pressure and temperature
 • Non-toxic
 • Supercritical CO2 behaves as a nonpolar solvent
   such as heptane
 • Polar organic modifiers can be mixed with CO2
   for more polar samples
           SFC Applications
Industrial :

•   Synthetic oligomers, polymers / additives
•   Surfactants (polyglycols)
•   Oligo / polysaccharides, sucrose polyesters
•   Pesticides
•   Isocyanates
•   Dyes
•   Waxes
          SFC Applications

Biochemical :

•   Steroids
•   Prostaglandins
•   Fatty acids / lipids
•   Antibiotics
•   Drugs of abuse
            SFC Applications

Fossil Fuels :

• Fractionation of petroleum and coal-derived
• Hydrocarbon group analysis
• Simulated distillation
Other Applications of
         Supercritical Fluid

•   Supercritical Fluid Cleaning
•   Supercritical Fluid Drying
•   Supercritical Fluid Reactions
•   Micro Particles Formation
•   Supercritical Water Oxidation System
•   Others
Applications of Supercritical Fluid
          Technologies in Taiwan

         • IN THE PAST
Applications of Supercritical Fluid
          Technologies in Taiwan

         • AT PRESENT
Applications of Supercritical Fluid
          Technologies in Taiwan

        • IN THE FUTURE
Thanks For Your Attention !

•   林華經

•   國立清華大學化工系學士
•   國立清華大學生科所碩士
•   國立清華大學化工系博士班

•   友翔實業股份有限公司 儀器部經理
•   引光生物科技有限公司 研發部經理

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