digestio
of the s
simultan
Titratio
standard
reaction
equival
followin
weighs
molecu
being a
carry ou
content
Advant
A
method
reprodu
is not i
have di
poses a
time co
The ammo
on flask and
solution in
neously con
NH
on
The nitroge
d sulfuric o
n.
H2B
The conce
ent to the
ng equation
m grams us
Where vs a
lar weight o
analyzed to
ut the analy
t using the a
tages and D
Advantages
d for compa
ucibility hav
Disadvanta
n the form
fferent amin
considerab
nsuming to
nia gas tha
d into the re
the receivi
nverts the b
3 + H3BO3
en content i
r hydrochlo
BO3
- + H+
ntration of
concentrati
n can be u
sing a xM H
and vb are t
of nitrogen
take into ac
ysis. Once th
appropriate
Disadvanta
s. The Kjeld
arison agai
ve made it th
ages. It does
of protein.
no acid seq
ble hazard,
carry-out.
at is formed
eceiving flas
ing flask co
boric acid to
(boric acid)
is then estim
oric acid, us
H3BO3 (4
f hydrogen
ion of nitro
used to de
HCl acid sol
the titration
N. A blank
ccount any
he nitrogen
conversion
ages
dahl method
nst all othe
he major m
s not give a
. Different
quences. Th
as does the
d is liberat
sk - which c
onverts the
o the borate
) NH4
+ +
mated by tit
sing a suitab
4)
ions (in m
ogen that w
etermine th
lution for th
n volumes
k sample is
residual nit
content has
factor: %P
d is widely
er methods
method for th
measure o
proteins ne
he use of co
e use of som
ed from th
contains an
ammonia
ion:
H2BO3
- (bo
tration of th
ble indicator
moles) req
was in the
e nitrogen
he titration:
of the sam
usually ran
trogen whic
s been deter
rotein = con
used intern
s. Its unive
he estimatio
of the true p
eed differen
ncentrated
me of the po
e solution
n excess of b
gas into th
orate ion) (3
he ammoniu
r to determi
quired to re
original fo
concentrat
(5)
mple and b
n at the sam
ch may be i
rmined it is
nversion fac
nationally a
ersality, hig
on of protein
protein, sinc
nt correction
sulfuric aci
ossible cata
and moves
boric acid. T
e ammoniu
3)
um borate f
ine the endeach
the e
ood (Equati
tion of a s
blank, and
me time as t
in the reage
s converted
ctor × %N.
and is still t
gh precision
n in foods.
ce all nitrog
n factors be
id at high te
alysts The t
7
s out of the
The low pH
um ion, and
formed with
-point of the
nd-point is
ion 3). The
sample that
14g is the
the material
ents used to
to a protein
the standard
n and good
gen in foods
ecause they
emperatures
technique is
eHd
h
e
s