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H
ostetler
:
J
ournal of
AOAC I
nternational
V
ol
.
100, N
o
.
3, 2017
11
to locally sourced samples that were fortified with lutein or
β-carotene. All samples were prepared in triplicate, and the
SPIFAN samples with substantial carotenoid concentrations
were prepared at least 12 times (three replicates × 4 days).
Intermediate precision (RSD
iR
) was calculated as the RSD of
all replicates. Repeatability (RSD
r
) for triplicate samples was
calculated as the RSD, and for larger samples sizes, it was
estimated by performing a one-way analysis of variance on
the intermediate precision data and calculating the SD from
the within-day variance. Although SMPR 2014.014 does not
specify criteria for intermediate precision, the requirements
for repeatability and reproducibility are outlined in Table 8.
Precision data are summarized in Tables 9 and 10. For all
measurements in the range of 1–100 μg/100 g, RSD
r
was
≤5.8% for lutein and ≤5.1 for β-carotene. For measurements
>100 μg/100 g, RSD
r
was ≤1.1% for lutein and ≤1.7 for
β-carotene. RSD
iR
ranged from 1.6 to 5.9% for lutein and from
0.7 to 6.3% for β-carotene for measurements >1 μg/100 g.
For all measurements above 1 μg/100 g, the method met the
precision requirements of the SMPR.
Accuracy
Because there is currently no Certified Reference Material
for carotenoids in infant formula and adult nutritionals,
Table 8. Precision requirements from SMPR 2014.014
Sample concn, μg/100 g
Repeatability, % Reproducibility, %
1–100
8
15
>100–1300
5
10
Table 9. Precision data for lutein in SPIFAN matrixes and select additional matrixes
a
Matrix
SPIFAN code
n
cis
-Lutein,
μg/100 g RSD
r
, % RSD
iR
, %
trans
-Lutein,
μg/100 g RSD
r
, % RSD
iR
, %
Total lutein,
μg/100 g RSD
r
, % RSD
iR
, %
Child Formula Powder,
Placebo
00847RF00 3
<
b
NA
c
NA
<
NA
NA
<
NA NA
Infant Elemental Powder,
Placebo
00796RF 3
<
NA
NA
<
NA
NA
<
NA NA
AN High-Protein RTF,
Placebo
d
00821RF00 3
<
NA
NA
3.3
3.8
NA
3.3
3.8
NA
AN High-Fat RTF, Placebo 00820RF00 3
2.0
3.8
NA
4.2
4.6
NA
6.2
4.1
NA
IF Milk-Based RTF,
Placebo
e
EV4H2Q 3
<
NA
NA
0.5
5.7
NA
0.6
4.8
NA
SRM 1849a Powder
CLC10-B 3
<
NA
NA
<
NA
NA
<
NA NA
IF Milk-Based Partially
Hydrolyzed Powder
410057652Z 3
<
NA
NA
<
NA
NA
<
NA NA
IF Soy-Based Partially
Hydrolyzed Powder
410057651Z 3
<
NA
NA
<
NA
NA
0.3
11.5
NA
Toddler Formula
Milk-Based Powder
4052755861 12 3.7
1.2
2.2
21.9
3.6
3.8
25.5
3.1
3.4
IF Milk-Based Powder
4044755861 12 2.1
3.6
3.7
9.4
5.0
5.9
11.5
4.1
5.1
AN Powder
00859RF00 3
<
NA
NA
<
NA
NA
<
NA NA
Child Formula Powder
00866RF00 3
<
NA
NA
<
NA
NA
<
NA NA
IF Elemental Powder
00795RF 12
<
NA
NA
<
NA
NA
<
NA NA
IF with FOS/GOS Powder
f
50350017W1 12 0.3
12.3
14.3
0.9
2.9
5.2
1.2
3.4
4.2
IF Milk-Based Powder
(control)
K16NTAV 39 1.6
3.3
5.5
4.5
1.2
1.6
6.1
1.6
2.3
IF Soy-Based Powder
E10NWZC 12 0.6
5.7
8.0
1.6
3.2
3.4
2.2
2.8
3.1
IF Milk-Based RTF
EV4H2R 3
<
NA
NA
0.5
6.2
NA
0.7
16.9
NA
AN High-Protein RTF
00730RF00 12 1.9
4.1
4.4
3.1
2.4
3.0
4.9
2.9
3.4
AN High-Fat RTF
00729RF00 3
1.7
5.8
NA
3.5
3.3
NA
5.2
3.2
NA
AN High-Lutein Powder
—
g
3 21.4
0.3
NA
82.1
0.1
NA
104
0.2
NA
Chocolate Pediatric
Nutritional RTF
— 3 13.0
0.4
NA
127
1.1
NA
140
1.0
NA
IF RTF
— 3
1.5
3.8
NA
3.9
1.4
NA
5.5
2.0
NA
a
For powder samples, results were calculated using a factor of 25 g powder/225 g reconstituted weight.
b
< = Below the LOQ.
c
NA = Not applicable. RSDr not calculated for concentrations <LOQ; RSDiR not calculated if samples were all prepared on the same day.
d
AN = Adult Nutritional.
e
IF = Infant Formula.
f
FOS/GOS = Fructooligosaccharide/galactooligosaccharide.
g
— = Sample was sourced locally and was not part of the SPIFAN kit.
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