6.5 Recrystallization of CR. The following procedure has been found satis-
factory for recrystallizing CR for use in the purity determination: Dissolve
the CR using heat in the minimum amount of ethanol necessary. Add sufficient
water to initiate precipitation of the CR plus a slight excess. Filter through
a coarse filter paper by gravity, discarding the initial precipitate. Add
additional water to the filtrate. Filter and allow the CR on the filter paper
to dry. Redissolve the CR from the second filtration in ethanol and evaporate
to dryness. Determine the melting range. If the melting range does not fall
within a 71 to 74C range, recrystallize the CR.
6.6 Standard CR. CR of known purity for use in 18.104.22.168.2(b) may be obtained
from Commander, US Army Armament Research and Development Command, Product
Assurance Directorate, Chemical Systems Division, Aberdeen Proving Ground, MD
21010. Alternatively, the contractor may prepare his own standard CR and
obtain verification of its purity from Chemical Systems Division.
6.7 Sampling and testing precautions. This specification covers inspection
of chemical material which is potentially hazardous to personnel. All
applicable safety rules, regulations and procedures must be followed in the
sampling and testing of this material.
6.8 Packaging precaution. Styrofoam beads used as filler material cause
static charge buildup making handling of CR difficult and should not be used.
6.9 Supersession data. This specification supersedes and includes the
requirements of Edgewood Arsenal Purchase Description EA-R-1135, dated 9
Army - EA
Army - EA
Project No. 1365-A071