Final Year Project

gcouger gcouger at NoXSPAM.mercury.rfdata.net
Fri Jan 5 07:18:30 EST 2001

<chris_blencowe at my-deja.com> wrote in message
news:92vdpc$3ak$1 at nnrp1.deja.com...
: I am a final year Undergraduate at the University of Surrey, my
:  research project is looking at the effect of the addition of co-
: metabolic substrates upon the microbial degradation of
:  phenanthrene.
:  I am having trouble with extracting the phenanthrene from the soil I am
: using in order to assess its degradation using gas
:  chromatography.  I do not have access to working Soxhlet Extraction
: Apparatus nor the equipment to conduct an extraction using
:  Supercritical Carbon Dioxide, which seem to be the most popular
: methods.  Instead I have been using a simple hexane extraction
:  in order to try to recover the phenanthrene but this does not seem to
: be effective.  I have tried drying the soil samples to remove
:  the water content and increasing the amount of agitation the samples
: undergo.
:  Are the any further suggestions to improve this method and/or do you
: know of any other robust and yet simple methods for the
:  recovery of phenanthrene from soil?

Could  you be boiling off the phenanthrene when you dry you soil? Can you
find a solvent that water is soluble in and phenanthrene isn't ethanol or
acetone are good place to look. Does water mess up your extraction with
hexane. You can remove water from hexane with anhydours copper sulfate for
one of many things.

Do you have a hexane protocol.

Super critical CO2 is nice because it is nice clean and doesn't burn or
smell up the lab.

Where do you know you are having trouble and where do you think you are
having trouble? Can you say everything works up to here? Can you dye the
phenanthrene so you can see what is happening?

If you can atomize the problem down to this works and this doesn't you
have made a big step on the way to solving it.

Set down a make a list of every thing that phenanthrene is soluble in and
ever thing water is soluble in. You may want to get them out together and
separate them out in solution. Freeze it and pour off everything and leave
the water behind. Take advantage of vapor pressure differences and distill
and do fractional freezing to separate the fractions.. Not knowing the
properties of phenanthrene I can't guess but start shuffling around until
you find something. If heptane wont do it iso butane might or octane might
or either might.

Good luck
Gordon    W5RED
G. C. Couger gcouger at provlue.net  Stillwater, OK

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