RestekCorporation
(800) 356-1688
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anddisk elution twicewith fresh
aliquots ofmethylene chloride,
combining all eluates in the collection
tube.
FinalAnalysis:
Removewater from sample eluateby
passing it through approximately3
grams of anhydrous sodium sulfate.
Concentrate to1ml and analyze 1µl by
GC/MS.
Environmental
SPEExtraction forEPAMethod 525.1
note
A
pplications
cat.#59557
EPAMethod 525.1Overview
EPAMethod525.1 is used for thedeterminationof organic compounds indrinkingwater by liquid-solid extraction and capillary
columngas chromatograph/mass spectrometry. It is applicable to awide rangeof organic compounds that are efficientlyparti-
tioned from thewater sample onto aC18organic phase chemicallybonded to a solid silicamatrix in a cartridge or disk.
EPAmethods are
available from the
NationalTechnical
InformationService:
703-487-4650
SIMDisk
™
-GF
extractiondisks canbe used inEPAMethod 525.1
This procedurewas followed todemonstratemethod equivalency:
lowvacuumuntil thewater almost
reaches the top surface of the disk. It is
preferable to leave extra liquid above
the disk rather than allow any air to
contact the surface of the disk.
SampleAddition:
Add the sample onto the disk, directly
to the filmofwater left from the
conditioning step.Adjust thevacuum to
10 in.Hg (35kPa) for a flow rate of
approximately100ml perminuteuntil
the entire sample has beenpassed
through thedisk.
DiskDrying:
After the samplehas beenprocessed,
draw air through thediskunder vacuum
at approximately15 in.Hg (50kPa) for
approximately5minutes.
AnalyteElution:
Release systemvacuum. Insert the
sample collection rack and collection
vessels. Reassemble the apparatus.Add
5mlmethylene chloridedirectly to the
sample bottle andgently swirl to rinse
all inner surfaces of the bottle.Allow
the sample bottle to stand for 1 to2
minutes and transfer themethylene
chloride to the diskusing a glass pipet.
Rinse the reservoir sides in the process.
Draw the solvent through the disk at 5
in.Hg (17kPa). Repeat the bottle rinse
1
SIMDisk
™
-GF
:
cat.# 24004, 20-pack
SamplePretreatment:
Allow1 liter of deionizedwater to
equilibrate to room temperature in a
narrow-mouthamber glassbottle.
Adjust sample pH to less than2with
6Mhydrochloric acid, being careful not
toover acidify the sample.Additionof
toomuchHC
1
can cause the formation
of acidic extracts.
ApparatusAssembly:
Assemble the47mm apparatus. Place
theSIMDisk
™
-GFdisk in the
Diskcover
™
-47 filter support,wrinkled
sideup.
DiskPrecleaning:
Add5ml ofmethylene chloride to the
top surfaceof thedisk and immediately
draw throughunder vacuum at 15 in.
Hg (50kPa). Continue todrawvacuum
at 15 in.Hg (50kPa) for 5minutes to
remove all solvent.
DiskConditioning:
Add5mlmethanol to the top surface of
thedisk and immediately apply low
vacuum (1- 2 in.Hg, 3-7kPa).Draw
throughuntil the top surfaceof the
methanol is just above the disk.Donot
allow any air topass through the diskor
reach the top surface of the disk.
Immediately add5ml of deionized
water to the disk anddraw through at
