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(b)
Hot plate
.—Model 53015, Lindburg/Blue M (Watertown, WI), or equivalent.
(c)
ICP-OES instrument
.—Thermo 6500 Duo View (Thermo Scientific, Cambridge, UK), or
equivalent.
(d)
Gated riffle splitter
.—SP-177 Jones Standard Aluminum Splitter (Gilson Co., Inc., Lewis
Center, OH), or equivalent.
(e)
Grinding mill
.—Mikro-Samplemill (Pulverizing Machinery, Summit, NJ), or equivalent.
B.
Reagents (Alternative B)
(a)
Hydrochloric acid
.—HCl, 35–38%, trace metal grade, Cat. No. A508-500 (Fisher Scientific,
Pittsburgh, PA).
(b)
Ammonium dihydrogen phosphate
.—NH
4
H
2
PO
4
, FW 115.03, trace metal basis, purity
>99.999%, Cat. No. 204005-100G (Sigma-Aldrich).
(c)
Potassium chloride
.—KCl, FW 74.55, trace metal basis, purity > 99.99%, Cat. No. 204099-
250G (Sigma-Aldrich).
(d)
Scandium oxide
.—Sc
2
O
3
, FW 137.91, Item No. OX21-5N (Stanford Materials Corp., Irvine,
CA).
(e)
Nitric acid
.—HNO
3
, 69.2%, certified ACS plus grade, Cat. No. A200 C212 (Fisher Scientific).
(f)
Triton X-100
.—Polyethylene-glycol
p
-tert-octylphenyl ether, 4-(C
8
H
17
)C
6
H
4
(OCH
2
CH
2
)
n
OH
(
n
approximately 10), FW 624, Cat. No. BP151-500 (Fisher Scientific).
(g)
Cesium chloride
.—CsCl, FW 168.36, trace metal basis, purity >99.999%, Cat. No.
203025-50G (Sigma-Aldrich).
(h)
Lithium nitrate
.—LiNO
3
ReagentPlus grade, FW 68.95, Cat. No. 227986-1KG (Sigma-Aldrich).
(i)
10000 μg/mL Be stock standard
.—In 5% HNO
3
, Cat. No. PLBE-10-500 (Exaxol Corp.,
Clearwater, FL).
(j)
10000 μg/mL Sc stock standard
.—Weigh 15.3374 g scandium oxide [(
d
) above] into a 600
mL beaker. Add 300 mL deionized water, then slowly add 100 mL nitric acid [(
e
) above]. Heat
solution on a hotplate to a gentle boil, and continue boiling until the solution becomes clear.
(k)
1% Triton X
.—Pipet 10 mL Triton X-100 solution [(
f
) above] into a 1 L flask. Bring to
volume with deionized (or equivalent) water and mix.
(l)
Internal standard/ionization buffer (60 μg/mL Sc in 0.035 M CsCl and 2% HNO
3
).
—Add 6
mL 10000 µg Sc/mL stock standard [(
j
) above], 6 g CsCl [(
g
) above], 20 mL HNO
3
[(
e
) above],
and 2 mL 1% Triton X [(
k
) above] to a 1 L flask containing approximately 500 mL deionized (or
equivalent) water. Bring to volume with deionized water and mix. If LiNO
3
is used as the ionic
buffer, replace the CsCl with 8 g LiNO
3
[(
h
) above]. If Be is used as an internal standard, add 1
Candidates for 2016 Method of the Year
252