method for the determination of Ca ranged between 1.1%
(dieteticmilk powder) and 3.9% (infant cereals). The RSD
R
ranged between 2.9% (chocolate milk powder) and 5.0%
(peanut butter). The HorRat value should not exceed 1.5.
Table 29 shows that the present method has an acceptable
precision for the determination of Ca in all foodstuffs
analyzedwithCa concentration above the estimatedQL. The
truenessas
z
-score (Table30) iscalculated torange from–0.6
(chocolate milk powder) to 0.2 (peanut butter). The results
indicate that this method can determine, with sufficient
precision, from9870 to411mg/kg.
(
b
)
Copper
.—Table 29 presents estimated performance
characteristics of the ICP-AESmethod for Cu. The RSD
r
of
themethod for thedeterminationofCu rangedbetween1.8%
(wheat gluten) and 5.0% (infant cereals). The RSD
R
ranged
between4.4%(wheat gluten) and12.0%(infant cereals). The
HorRat value shouldnot exceed1.0. Table 29 shows that the
present method has an acceptable precision for the
determination of Cu in all foodstuffs analyzed with Cu
concentration above or close to the estimated QL. The
trueness, expressed as
z
-score (Table 30), is calculated to
range from–0.7 (wheat gluten) to 0.03 (peanut butter). The
results indicate that thismethodcandetermine,withsufficient
precision, from6.09 to1.94mg/kg.
(
c
)
Iron
.—Table 29 presents estimated performance
characteristics of the ICP-AESmethod for Fe. The RSD
r
of
themethod for the determinationof Fe rangedbetween1.5%
(infant cereals) and 5.0% (peanut butter). The RSD
R
ranged
between4.1%(wheat gluten) and14.9%(peanut butter). The
HorRat value shouldnot exceed1.5. Table 29 shows that the
present method has an acceptable precision for the
determination of Fe in all foodstuffs analyzed with Fe
concentrationabovetheestimatedQL.Thetruenessas
z
-score
(Table 30) is calculated to range from–2.2 (wheat gluten) to
0.2 (dietetic milk powder 2). The results indicate that this
method can determine, with sufficient precision, from169.9
to16.4mg/kg.
(
d
)
Potassium
.—Table 29 presents estimated
performance characteristics of the ICP-AES method for K.
The RSD
r
of the method for the determination of K ranged
between 0.9% (dietetic milk powder) and 1.6% (peanut
butter). The RSD
R
ranged between 1.2% (dietetic milk
powder) and 7.8%(wheat gluten). TheHorRat value should
not exceed1.5.Table29shows that thepresentmethodhasan
acceptable precision for the determination of K in all
foodstuffsanalyzedwithKconcentrationabove theestimated
QL. The trueness as
z
-score (Table 30) is calculated to range
from–1.8 (wheat gluten) to 0.7 (peanut butter). The results
indicate that this method can determine, with sufficient
precision, from9090 to472mg/kg
(
e
)
Magnesium
.—Table 29 presents estimated
performance characteristics of the ICP-AESmethod forMg.
TheRSD
r
of themethod for the determination ofMg ranged
between 1.2% (dietetic milk powder) and 3.4% (infant
cereals). The RSD
R
ranged between 2.9% (dietetic milk
powder) and 5.4%(infant cereals). TheHorRat value should
not exceed1.5.Table29shows that thepresentmethodhasan
acceptable precision for the determination of Mg in all
foodstuffs analyzed with Mg concentration above the
estimatedQL.The truenessas
z
-score (Table30) iscalculated
to range from–1.8 (wheat gluten) to 0.6 (peanut butter). The
results indicate that thismethodcandetermine,withsufficient
precision, from1779 to444mg/kg.
(
f
)
Manganese
.—Table 29 presents estimated
performance characteristics of the ICP-AESmethod forMn.
TheRSD
r
of themethod for the determination ofMn ranged
between 1.4%(wheat gluten) and 7.2%(infant cereals). The
RSD
R
ranged between 6.5% (chocolate milk powder) and
9.2% (infant cereals). The HorRat value should not exceed
1.0.Table29shows that thepresentmethodhasanacceptable
precision for the determination of Mn in all foodstuffs
analyzedwithMnconcentrationabove theestimatedQL.The
truenessas
z
-score (Table30) iscalculated torange from–1.1
(wheat gluten) to 0.1 (dietetic milk powder). The results
indicate that this method can determine, with sufficient
precision, from16.0 to0.405mg/kg.
(
g
)
Sodium
.—Table 29 presents estimated performance
characteristics of the ICP-AESmethod for Na. The RSD
r
of
themethod for thedeterminationofNa rangedbetween1.2%
(wheat gluten and dietetic milk powder) and 3.9% (infant
cereals). The RSD
R
ranged between 2.2% (chocolate milk
powder) and 5.5%(infant cereals). TheHorRat value should
not exceed 1.0. Table 29 shows that the present method has
an acceptable precision for the determination of Na in all
foodstuffs analyzed with Na concentration above the
estimatedQL.The truenessas
z
-score (Table30) iscalculated
to range from–1.6 (dietetic milk powder and wheat gluten)
to –0.03 (peanut butter). The results indicate that this
method can determine, with sufficient precision, from4890
to1420mg/kg.
(
h
)
Phosphorus
.—Table 29 presents estimated
performance characteristics of the ICP-AES method for P.
The RSD
r
of the method for the determination of P ranged
between 1.2%(wheat gluten) and 2.0%(peanut butter). The
RSD
R
rangedbetween2.1%(infant cereals) and3.3%(wheat
gluten). The HorRat value should not exceed 1.0. Table 29
shows that thepresentmethodhas anacceptableprecision for
the determination of P in all foodstuffs analyzed with
P concentration above the estimated QL. The trueness as
z
-score (Table 30) is calculated to range from –2.0 (wheat
gluten) to 0.8 (peanut butter). The results indicate that this
method can determine, with sufficient precision, from 4320
to2190mg/kg.
(
i
)
Zinc
.—Table 29 presents estimated performance
characteristicsof theICP-AESmethodforZn.TheRSD
r
of the
method for the determination of Zn ranged between 1.4%
(wheat gluten) and 3.0% (infant cereals). The RSD
R
ranged
between 3.8% (infant cereals) and 6.0% (peanut butter). The
HorRat value should not exceed 1.0. Table 29 shows that the
present method has an acceptable precision for the
determination of Zn in all foodstuffs analyzed with Zn
concentrationabove the estimatedQL. The trueness as
z
-score
(Table30) iscalculatedtorangefrom–1.7(wheatgluten) to1.1
P
OITEVINETAL.
: J
OURNALOF
AOACI
NTERNATIONAL
V
OL
. 92,N
O
. 5, 2009
1513
MTE-01
FORWORKINGGROUP/ERPUSEONLY
DONOTDISTRIBUTE
