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P
oitevin
:
J
ournal of
AOAC I
nternational
V
ol
.
95, N
o
. 1, 2012
185
> 0.99995 for all recommended lines except for the potassium
line (R
2
= 0.99924).
LOQ
The LOQ of elements (mg/kg): Ca (150); Cu (2); Fe (10);
K (200); Mg (50); Mn (0.05); Na (100); P (100); and Zn (5)
were estimated in real matrixes with satisfactory recovery,
repeatability RSD
r
, and reproducibility RSD
iR
values obtained
for elements present at these concentrations (e.g., Ca, Cu, Fe, K,
Na, and P in corn bran; Mg and Zn in sterilized cream, and Mn
in nonfat milk powder).
Selectivity
Recovery values ranged between 88 and 115% in all spiked
food-grade salt solutions with SDs between 0.1 and 18.8% for
spiking with element of interest that ranged between 0.01 and
60 mg/L.
Recovery
Recovery values ranged between 79 and 120% for all
elements in all matrixes for concentrations between 0.26 mg/kg
(Mn) and 16 900 mg/kg (K).
Repeatability and Reproducibility/Uncertainty
RSD
r
and RSD
iR
values for all elements in all matrixes
ranged between 0.6 and 16.9% and 0.7 and 23.3%, respectively,
for concentrations between 0.26 mg/kg (Mn) and 16 900 mg/kg
(K). Calculated derived relative uncertainty (U) values for all
elements in all tested matrixes ranged from 1 to 26% for all
elements in the seven tested matrixes.
Ruggedness
Recovery values for all elements in all matrixes ranged
between 67 and 118%. RSD
r
and RSD
iR
values for all elements
in all matrixes ranged between 0.4 and 18.9% and between 1
and 73.6%, respectively, for concentrations between 0.26 mg/kg
(Mn) and 16900 mg/kg (K). General applicability of the method
is limited by less analytical experience and competency
regarding sample preparation (e.g., sample homogeneity and
adapted digestion program) and ICP analysis (adapted ion
buffering and use of robust conditions).
Ring Trial Classical Statistics
The ring trial involved nine Nestlé laboratories that
volunteered to independently participate in the nutritional
elements study of five matrixes. This specific procedure enabled
participants to independently and objectively analyze ring trial
samples, adding their contribution to the final validation of the
method.
See
Tables
2011.14A
–
I
.
Recovery
Recovery values ranged between 87 and 105% for all
elements in all matrixes for concentrations ranging between
0.4 mg/kg (Mn) and 9700 mg/kg (Ca).
Repeatability and Reproducibility
RSD
r
and RSD
R
values for all elements in all matrixes
ranged between 1.0 and 6.8% and between 1.9 and 12.5%,
respectively, for concentrations between 0.4 mg/kg (Mn) and
9700 mg/kg (K).
HorRat
HorRat values ranged between 0.4 and 1.2 for all elements in
all matrixes for concentrations ranging between 0.4 mg/kg (Mn)
and 9700 mg/kg (Ca).
Recommendations
From the data presented in this paper, the method is suitable
for detecting calcium, copper, iron, magnesium, manganese,
potassium, phosphorus, sodium, and zinc in fortified food products
by microwave digestion and ICP-OES. It is recommended that
the method be adopted as an Official First Action Method of
AOAC INTERNATIONAL.
References
(1) Poitevin, E., Nicolas, M., Graveleau, L., Richoz, J., Andrey, D.,
& Monard, F.
(2009) J. AOAC Int. 92 , 1484–1518(2) Rousseew, P., & Croux, C. (1993)
J. Am. Stat. Assoc.
88
,
1273–1283.
doi.org/10.2307/22912672011.14 (MTE-01) MLT
FOR ERP USE ONLY
DO NOT DISTRIBUTE