262 Nuclear Forensic Analysis
in 10 M HCl, and the resulting solution passed through an anion-exchange col-
umn.
A
mericium
i
s
n
ot
a
dsorbed
b
y
t
he
r
esin,
b
ut
Np i
s
l
eft
b
ehind
o
n
t
he
c
olumn.
T
he
e
luent
w
as
e
vaporated
t
o
d
ryness,
t
he
r
esidue
r
edissolved
i
n
1
0
M H
Cl
(
+1drop
of H
NO
3
), and the anion-exchange step repeated with a fresh column.
T
he
t
emporal
m
idpoint
of t
his
c
olumn
w
as
r
ecorded
a
s
t
he
A
m–Np
s
eparation
t
ime.
A
fter
4
0days,
t
he
s
olution
w
as
a
gain
p
assed
t
hrough
a
n
a
nion-exchange
c
olumn.
N
eptunium
t
hat
h
ad
g
rown
i
nto
t
he
s
ample
o
ver
t
he
d
ecay
i
nterval
w
as
s
orbed
b
y
t
he
r
esin.
A
gain,
t
he
t
emporal
m
idpoint
of t
he
c
olumn
s
erved
a
s
t
he
reference time for the end of the decay interval. The Np fraction was recovered
f
rom
t
he
c
olumn,
p
ur