5-Hydroxy quinolilne solution (2.5 percent). Dissolve 12.5
grams of 3-hydroxyquinoline in 25 ml. of glacial acetic acid by warming
gently on the hot plate.
Dilute to 500 ml. with water.
before using if not clear.
Add 12 ml. of 3-hydroxyquinoline solution
to about 500 ml. of water, add 30 ml. of ammonium hydroxide (1 to 1), and
Prepare just before using.
dilute to 500 ml.
Weigh a 1 gram sample into a covered 400 ml.
Boil down to
beaker and add 10 ml. of water and 35 ml. of nitric acid.
a volume of about 20 ml. and acid 5 ml. of perchloric acid.
Add about 50
to strong fumes of perchloric acid and fume for 1 minute.
ml. of water and if the solution is not clear, filter, and wash with
Dilute to about 200 ml. with water and add 10 ml, of
Make just alkaline to litmus paper with ammonium
solution (2 .5 percent).
bydroxide (1 to 1 and add 20 ml. of ammonium hydroxide (1 to 1) in excess,
(use 2 thermometer)
Wash down and remove the litmus paper.
Cool to about 15°C, in a cold
and digest at that temperature for 30 minutes.
water bath and filter through a tared sintered glass crucible of medium
Transfer the precipitate to the crucible and wash four times
Dry at 135°C
Finally wash twice with cold water
with the wash solution.
Calculate as follows:
for 90 minutes, cool, and weigh