cereals-7.pdf

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Adjunct Materials
Cereals–7
Page 1 of 1
ASH
Reagent
(a) Ammonium carbonate solution, (NH
4
)
2
CO
3
, 10%.
Apparatus
(a)
Ashing dishes or crucibles,
of platinum, porcelain,
or fused silica, large enough to hold 2–5 g ground
cereal adjunct.
(b)
Muffle furnace,
regulated to 550°C.
(c)
Desiccator.
(d)
Analytical balance
and
weights.
Method
Weigh 2–5 g (±0.001 g) of ground cereal (Adjunct
Materials, Cereals-5)
into ignited, cooled, and weighed
ashing dish. Ignite at approximately 550°C until color of
ash is white to pale gray; 2 hr is usually sufficient. If
white or nearly white ash is not obtained, cool and
moisten residue with a little ammonium carbonate
solution (reagent a). Dry and ignite at 550°C until
weight remains constant. Cool ash and dish in desiccator
and weigh.
Calculations
Calculate weight of ash as % of sample by the
formulas,
Ash, as-is, %
=
(
A
−
B
)
×
100
W
and
Ash, dry basis, % =
Ash, as is %
×
100
100
−
M
in which,
A
= wt of dish + ash,
B
= wt of dish,
W
= wt of sample of cereal adjunct,
M
= Moisture content of cereal adjunct, %.
Example
M,
% = 11.2.
W
= 5.078 g.
A
= 35.579 g.
B
= 35.543 g.
Ash, as-is, % =
(
35.579
−
35.543
)
×
100
=
0.71
5.078
0.71
×
100
=
0.80
100
−
11.2
Ash, dry basis, % =
1958, rev. 1976
doi: 10.1094/ASBCMOA-Cereals-7

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