25
10.
Using the 5 milliliter pipettor from the basic
L2000
DXT
system, add 5 ml of the L2000
Extraction solution to the black-capped tube. Tighten the cap securely and shake the tube
vigorously until the foam and dark color disappears. Vent the tube by partially unscrewing
the cap while holding the tube upright. Squeeze the test tube slightly while retightening
the cap and shake a second time. Vent again, retighten cap and stand the tube upside-
down on the flat top of the cap and allow to settle for two minutes.
11.
Place a filter funnel in one of the 20 ml glass vials marked with a sample number. Position
the black-capped test tube directly over the top of the funnel and open the dispenser
nozzle. Dispense the solution by carefully squeezing the sides of the tube. Allow the
solution to pass thorough the funnel, but remove the funnel before any oil can get through.
Allow the filtered solution to cool for five minutes. The sample is now ready for analysis
with the
L2000
DXT
Analyzer.
Water Samples
High Range (5-2000 ppm)
1.
Fill sample tube with 10 grams of water sample.
2.
Add 10 mL of isooctane extraction solvent and shake vigorously for 30 seconds.
3.
Allow to separate into two phases for a minimum of 2 minutes. (If a emulsion forms, add
sodium sulfate
2
, shake and allow to separate again). Using the disposable plastic pipette
remove 5 mL of the top solvent layer and add to the black capped reaction tube. Proceed
with test as for an oil sample and quantify using the appropriate
L2000
DXT
method.
Low Range (20 ppb - 5 ppm)
1.
Collect sample in 1 quart narrow mouth glass bottle with zero head space. Cap tightly and
store on ice until analysis.
2.
When ready to analyze the sample, invert sample container gently once or twice and, using
a plastic pipette, remove 35 mL of water from the sample jar by weighing 35 grams of
water into a tared waste container and discard. Then add 10 mL of isooctane to sample
container and shake vigorously for 2 minutes.
3.
Add sufficient chlorine free distilled water to bring the water level up into the neck of the
sample bottle (the solvent level should be just shy of the top of the neck) and allow to set
for 3 minutes.
4.
Withdraw 5 mL of the upper solvent layer (
Do not remove any water with the solvent
),
add to the black capped reaction tube and cap tube tightly.
2
Available from major chemical suppliers.