Transfer a 1 gram sample to a 400 ml. beaker and
add 10 ml. of water and 35 ml. of nitric acid.
Cover with a watch glass,
warm on the lot plate until the vigorous reaction ceases, and then boil
Add 10 ml. of perchloric acid
down to a volume of approximately 20 ml.
and boil down to a volume of 3 or 4 ml.
cool, add water, and dilute to
500 ml. in a volumetric flask.
Pipet a 25 ml. aliquot (equivalent to
0.05 gram of sample) into the original beaker , and add 50 ml. of water,
15 ml. of ammonium citrate solution (20 percent) , and 150 ml. of ma gnesium
Add ammonium hydroxide (1 to 1 with stirring until the precipi-
tate starts to appear, stop the addition of the ammonium hydroxide, and
stir for about 2 minutes.
Add 25 ml. of ammonium hydroxide (1 to 1) in
Filter through a Whatman No. 40
excess and allow to stand overnight.
filter paper, wash the precipitate into the filter paper with ammonium
hydroxide (1 to 50), and then wash three t imes with ammonium hydroxide
Dissolve the precipitate off the filter paper into the
(1 to 50).
orignal 400 ml. beaker with two 12 ml. portions of hydrochloric acid
with hot hydrochloric acid (1 to 50).
(1 to 1) and then wash several times
Add 1 ml. of ammmonium citrate solution and 4 ml. of magnesia mixture and
again precipitate by adding ammonium hydroxide as previously described.
Add 10 ml. excess ammonium hydroxide ( 1 to 1) and allow to stand overnight.
Filter through a Whatman No. 40 filter paper, transfer the precipitate
to the filter paper with ammonium hydroxide (1 to 50), and wash five times
Transfer the filter paper and precipitate
ammonium hydroxide (1 to 50).