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|  MIL-W-215D
4.2.4.4 Insoluble matter in toluene. Safety precautions: Wear dust-proof and
splash-proof safety goggles and a faceshield (when skin contact is possible), rubber
gloves, and robber apron when handling or analyzing phosphorus. A rubber glove may be
omitted from one hand while pipetting a sample. Never use the mouth to pipet phospho-
rus. Check all glassware for cracks before use. Ensure that personnel are not exposed to
airborne concentrations of white phosphorus in excess of the permissible exposure limit
contained in 29 CFR 1910.1000 or, when applicable, a more stringent workplace exposure
standard. Determine insoluble matter in toluene in accordance with procedure A or proce-
dure B.
(a) Procedure A. Place a spot plate into a large evaporating dish and add 350
to 400 mL of hot water, making sure that the spot plate is completely covered with water.
Insert the tip of a 10-mL Mohr pipet containing the specimen under the water in the
evaporating dish and place the specimen on three sections of the spot plate, forming
pellets having a weight of approximately 1 gram (g) each. Cool until the pellets solidify.
Fill a Nesbitt absorption bulb with carbon dioxide gas and weigh. Immerse the three
pellets in acetone to dissolve most of the water and then add them to the Nesbitt absorp-
tion bulb. Fill the Nesbitt absorption bulb with carbon dioxide gas, flush thoroughly, and
weigh. Transfer the pellets from the Nesbitt absorption bulb to a 1000-mL beaker con-
taining 800 mL of toluene. (Xylene may be used in place of the toluene.) Place the
beaker on a hot plate or steam bath and heat until the pellets have gone into solution. Do
not add more than 1.0 g of specimen to each 100 mL of toluene as spontaneous ignition
of the solution can occur if there is more than 1.5 percent by weight of specimen in
toluene. Filter the toluene solution through a tared medium porosity sintered glass cruci-
ble. (NOTE: Prior to use, wash the medium porosity sintered glass crucible with toluene,
dry in an oven at 100C for 30 minutes, cool to room temperature in a desiccator, and
weigh.) Do not allow the crucible to become dry, Wash with warm toluene. Air dry in a
hood for 10 to 15 minutes. Wash with a small amount of water, dry the medium porosity
sintered glass crucible in an oven at 100C for 30 minutes, cool to room temperature in a
desiccator, and weigh. Calculate the percent insoluble matter in toluene as follows:
where: A = Weight of Gooch crucible and residue in grams,
B = Weight of Gooch crucible in grams,
C = Weight of Nesbitt absorption bulb, carbon dioxide, and pellets in grams,
and
D = Weight of Nesbitt absorption bulb filled with carbon dioxide in grams.
(b) Procedure B. Melt the specimen by submerging its container in hot water
having a temperature of about 55C. Stand a 50-mL centrifuge tube in a beaker and
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