In
the
initial
stage
of
this
work,
two
potentiometric
methods
were
used
to
determine
the
salt
(sodium
chloride)
content
in
bread
and
dough
samples
from
several
cities
in
the
north
of
Portugal.
A
reference
method
(potentiometric
precipitation
titration)
and
a
newly
developed
ion-selective
chloride
electrode
(ISE)
were
applied.
Both
methods
determine
the
sodium
chloride
content
through
the
quantification
of
chloride.
To
evaluate
the
accuracy
of
the
ISE,
bread
and
respective
dough
samples
were
analyzed
by
both
methods.
Statistical
analysis
(0.05
significance
level)
indicated
that
the
results
of
these
methods
did
not
differ
significantly.
Therefore
the
ISE
is
an
adequate
alternative
for
the
determination
of
chloride
in
the
analyzed
samples.
To
compare
the
results
of
these
chloride-based
methods
with
a
sodium-based
method,
sodium
was
quantified
in
the
same
samples
by
a
reference
method
(atomic
absorption
spectrometry).
Significant
differences
between
the
results
were
verified.
In
several
cases
the
sodium
chloride
content
exceeded
the
legal
limit
when
the
chloride-based
methods
were
used,
but
when
the
sodium-based
method
was
applied
this
was
not
the
case.
This
could
lead
to
the
erroneous
application
of
fines
and
therefore
the
authorities
should
supply
additional
information
regarding
the
analytical
procedure
for
this
particular
control.