P
OITEVINETAL.
: J
OURNALOF
AOACI
NTERNATIONAL
V
OL
. 92,N
O
. 5, 2009
1495
Table 11. SLVstudy: accuracy, precision, andHorRat values found for calciuminsevencertifiedand in-house referencematerialsusing recommendedand
alternate lines
Material description
Line
Reference
value,mg/kg
a,b
Median±U,
mg/kg
c
Recovery,%
P
-value
d
SD
r
,mg/kg
e
SD
iR
,mg/kg
f
RSD
r
,% RSD
iR
,% HorRat
g
Sterilizedcream
Ca
h
845±18
756±132
90±5
0.07
72
125
9.5
16.5
2.8
Ca
i
726±132
86±5
0.02
67
112
9.3
15.4
2.6
Chocolatemilkpowder
Ca
h
9870±124 10092±343
102±2
0.21
135
303
1.3
3.0
0.7
Ca
i
9882±179
100±1
0.93
117
133
1.2
1.3
0.3
Infant cereals
Ca
h
6000±44
6189±249
103±1
0.05
151
219
2.4
3.5
0.8
Ca
i
5983±215
100±1
0.82
160
204
2.7
3.4
0.8
Cornbran
Ca
h
420±19
435±29
104±5
0.60
6
20.0
1.4
4.5
0.7
Ca
i
424±24
101±5
0.97
6
14
1.4
3.3
0.5
Dieteticmilkpowder 1
Ca
h
3020±15
3047±56
101±1
0.35
33
49
1.1
1.6
0.3
Ca
i
2987±54
99±1
0.11
22
49
0.7
1.7
0.4
Pet food
Ca
h
6190±140
6580±317
106±3
0.05
94
192
1.4
2.9
0.7
Ca
i
6410±212
104±3
0.18
92
150
1.4
2.3
0.5
Nonfatmilkpowder
Ca
h
13000±250 13070±988
101±3
0.86
206
908
1.6
6.9
1.8
Ca
i
12910±813
99±3
0.80
222
735
1.7
5.7
1.5
a
SDexpressedashalf of stateduncertainty (NISTandLGCcertifiedmaterials) givenas95%confidence interval.
b
SDexpressedasa reproducibilitySD(in-house referencematerials) calculatedaccording to robust statistics (29).
c
Uncertainty (U) estimated throughsimplifiedapproach (30, 31).
d
Statisticevaluationof robust
t
-test: Satisfactory result (
P
>0.05); questionable result (0.01<
P
<0.05); unsatisfactory result (
P
<0.01).
e
SD
r
=SDof repeatability.
f
SD
iR
=SDof intermediate reproducibility.
g
HorRat =RatiousingRSD
iR
andHorwitzdenominator according to ref. 32.
h
Recommended line for ICP-AESanalysis.
i
Alternateconfirmatory lines for ICP-AESanalysis.
MTE-01
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