P
OITEVINETAL.
: J
OURNALOF
AOACI
NTERNATIONAL
V
OL
. 92,N
O
. 5, 2009
1509
Table 25. MD1–4 ruggedness tests: accuracy, precision, andHorRat values found formanganese in threecertifiedand in-house referencematerialsusing
recommended lines (MD1,MD2,MD3) andalternate2MnII line (MD4)
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
Cornbran
MD1
2.55±0.15
2.36
93±6
0.22
0.03
0.05
1.1
2.1
0.1
MD2
2.27
89±5
0.08
0.04
0.08
1.9
3.5
0.2
MD3
2.17
85±5
0.02
0.04
0.08
2.0
3.7
0.2
MD4
2.37
93±6
0.23
0.03
0.04
1.4
1.7
0.1
Dieteticmilkpowder 1
MD1
12.70±0.85
12.45
98±7
0.77
0.16
0.16
1.2
1.3
0.1
MD2
12.31
97±7
0.65
0.12
0.22
0.9
1.7
0.1
MD3
11.71
92±6
0.25
0.12
0.22
1.0
1.8
0.1
MD4
12.77
101±7
0.93
0.16
0.14
1.2
1.1
0.1
Nonfatmilkpowder
MD1
0.26±0.03
0.22
85±10
0.18
0.01
0.02
4.5
8.3
0.3
MD2
0.23
90±11
0.37
0.01
0.02
4.9
6.9
0.2
MD3
0.31
118±14
0.25
0.02
0.03
6.7
9.7
0.4
MD4
0.21
82±10
0.10
0.01
0.01
4.8
4.3
0.2
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
