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6.
Using the 5 mL pipettor, add five milliliters of extract solution to the black-capped tube.
Tighten the cap securely and shake vigorously until the foam and dark color disappear.
Vent the tube by partially unscrewing the black cap while holding the tube upright.
Squeeze the test tube slightly while re-tightening the cap, and shake the tube vigorously
for 20 seconds more. Vent again, tighten cap and stand the tube upside-down on the flat
top of the cap and allow to settle for two minutes.
7.
Place a polyethylene filter funnel in one of the 20 mL glass vials marked with the sample
number. Position the black-capped test tube directly over the top of the funnel and open
the dispenser nozzle. (See Figure 3) Dispense the solution by carefully squeezing the
sides of the tube. Stop as soon as the first drop of the organic solvent appears. Allow the
solution to pass through the funnel, but remove the funnel before any oil can get through.
Allow the solution to cool for five minutes. The sample is now ready for analysis.
Two-Step Procedure for Soil Analysis:
1.
Using the metal spatula and the portable electronic balance supplied with the kit, weigh
out ten grams of the soil into the empty, white-capped test tube.
NOTE: Be careful not to
get any foreign material into the weighed sample, i.e. absorbent material, large rocks,
etc.
The empty tube can be tared by placing it on the balance and pressing the
<ON/OFF/ZERO> key.
2.
Add the contents of one break-top glass solvent vial to the test tube of soil sample.
Replace the cap tightly on the tube and shake contents for 3 minutes making sure the entire
soil sample is thoroughly wetted.
3.
Add the colored water component contained in the 6 ml black-capped vial to the test tube.
Recap tightly and shake for an additional 2 minutes.
4.
Allow the mixture to separate for 2 minutes.
5.
Remove the plunger from a syringe/filter unit in the foil package and remove the black-
dispensing cap from the reaction test tube and stand it in the rack.
6.
Remove the top layer from the soil test tube (solvent layer) using the polypropylene
pipette provided and while holding the syringe/filter over the reaction tube, add 7 ml to the
syringe/filter.
7.
Add solvent from the syringe/filter up to the 5 ml line of the black-capped test tube.
Replace the cap tightly on the tube.
8.
Break the bottom (colorless) ampule in the black-capped test tube by squeezing the sides
of the tube and shake the mixture for 10 seconds.
9.
Break the top (gray) ampule in the test tube and shake the tube vigorously for 10 seconds.
Allow the reaction to proceed for an additional 40 seconds (total of one minute), while
shaking intermittently several times.