1510
P
OITEVINETAL.
: J
OURNALOF
AOACI
NTERNATIONAL
V
OL
. 92,N
O
. 5, 2009
Table 26. MD1–4 ruggedness tests: accuracy, precision, andHorRat values found for sodiumin fivecertifiedand in-house referencematerialsusing
recommended lines
Material description
-test code
a
Reference
value,mg/kg
b,c
Median,mg/kg Recovery,%
P
-value
d
SD
r
,mg/kg
e
SD
iR
,mg/kg
f
RSD
r
,% RSD
iR
,% HorRat
g
Chocolatemilkpowder
MD1
1990±42
2029
102±2
0.43
31
59
1.5
2.9
0.4
MD2
2000
101±3
0.86
42
99
2.1
4.9
0.7
MD3
1981
100±2
0.85
29
68
1.5
3.4
0.5
MD4
1949
98±2
0.36
14
34
0.7
1.7
0.2
Infant cereals
MD1
1050±14
1105
105±3
0.12
53
89
4.8
8.1
1.0
MD2
1002
95±2
0.04
21
42
2.1
4.2
0.5
MD3
970
92±3
0.01
12
59
1.3
6.1
0.8
MD4
935
89±3
0.002
23
63
2.5
6.8
0.8
Cornbran
MD1
430±16
395
92±3
0.05
4
10
1.1
2.4
0.3
MD2
395
92±4
0.08
4
27
1.1
6.8
0.7
MD3
391
91±5
0.09
10
40
2.5
1.0
0.1
MD4
388
90±4
0.03
4
19
1.0
5.0
0.5
Dieteticmilkpowder 1
MD1
4920±30
4850
99±1
0.09
43
69
0.9
1.4
0.2
MD2
4870
99±1
0.31
40
110
0.8
2.4
0.4
MD3
4910
100±1
0.81
32
122
0.6
2.5
0.4
MD4
5000
102±1
0.09
39
77
0.8
1.5
0.2
Nonfatmilkpowder
MD1
4970±50
4890
98±1
0.15
66
71
1.3
1.4
0.2
MD2
4940
99±1
0.60
62
106
1.3
2.2
0.4
MD3
4810
97±1
0.02
66
98
1.4
2.0
0.3
MD4
4930
99±1
0.51
75
110
1.5
2.2
0.4
a
Ruggedness test usingdifferentmicrowavedigestionsystemsand ICP-AESequipment (Table1).
b
SDexpressedashalf of stateduncertainty (NISTandLGCcertifiedmaterials) givenas95%confidence interval.
c
SDexpressedasa reproducibilitySD(in-house referencematerials) calculatedaccording to robust statistics (29).
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.
MTE-01
FORWORKINGGROUP/ERPUSEONLY
DONOTDISTRIBUTE
