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Butler-Thompson et al.:
J
ournal of
AOAC I
nternational
V
ol.
98, N
o.
6, 2015
1657
Table 2011.10A. SLV repeatability precision data for vitamin B
12
Sample type
No. of replicates (duplicates on multiple days) Mean, µg/100 g RTF
SD
r
RSD
r
, %
Infant formula (NIST SRM 1849a)
18
42.4
a
1.39
3.27
Infant formula powder soy-based
12
0.415
0.0150
3.62
Infant formula powder milk-based
12
0.236
0.0083
3.52
Infant formula RTF milk-based
12
0.355
0.0083
2.34
Infant formula powder partial hydrolyzed milk-based
12
0.377
0.0132
3.50
Infant formula powder partial hydrolyzed soy-based
12
0.257
0.0090
3.51
Adult nutritional powder milk-based
12
0.299
0.0141
4.72
Adult nutritional RTF high protein
12
1.13
0.0250
2.21
Child formula powder
12
0.955
0.0225
2.36
Adult nutritional RFT high fat
12
1.65
0.0463
2.81
Infant elemental powder
12
0.540
0.0223
4.13
Adult nutritional powder low fat
12
0.666
0.0187
2.81
a
Results in µg/kg powder.
Table 2011.10B. SLV accuracy data for vitamin B
12
—spike recoveries at 100% of native level
Sample type
No. of replicates
(duplicates on multiple days)
Native level,
µg/100 g RTF Recovery, % RSD, %
Infant formula (NIST SRM 1849a)
4
42.6
a
95.7
5.32
Infant formula powder soy-based
6
0.404
98.2
5.32
Infant formula powder milk-based
4
0.236
104
4.32
Infant formula RTF milk-based
6
0.326
96.4
8.17
Infant formula powder partial hydrolyzed milk-based
4
0.347
98.2
6.34
Infant formula powder partial hydrolyzed soy-based
6
0.248
95.7
2.51
Adult nutritional powder milk-based
4
0.298
97.4
3.86
Adult nutritional RTF high protein
6
1.12
98.6
6.76
Child formula powder
4
0.109
98.2
7.98
Adult nutritional RFT high fat
4
1.59
102
1.61
Infant elemental powder
6
ND
b
105
4.45
Adult nutritional powder low fat
4
0.639
95.1
4.38
a
Results in µg/kg powder.
b
ND = Not detected.
Table 2011.10C. Interlaboratory study results for vitamin B
12
Sample type
Total No.
labs
Total No.
replicates
Mean,
µg/100 g
RTF
SD
r
SD
R
RSD
r
, % RSD
R
, % HorRat
a
Infant formula (NIST SRM 1849a)
10
20
43.7
b
3.01
3.86
6.90
8.84
0.34
Infant formula powder soy-based
10
20
0.428 0.0208 0.0305 4.85
7.13
0.20
Infant formula powder milk-based
9
18
0.227 0.0111 0.0202 4.90
8.90
0.22
Infant formula RTF milk-based
9
18
0.272 0.0257 0.0427 9.46
15.7
0.40
Infant formula powder partial hydrolyzed milk-based
11
22
0.373 0.0200 0.0694 5.35
18.6
0.50
Infant formula powder partial hydrolyzed soy-based
10
20
0.250 0.0244 0.0487 9.77
19.5
0.50
Adult nutritional powder milk-based
10
20
0.300 0.0270 0.0416 8.99
13.8
0.36
Adult nutritional RTF high protein
10
20
1.08
0.0730 0.190 6.74
17.5
0.55
Child formula powder
8
16
0.967 0.0289 0.0342 2.98
3.54
0.11
Adult nutritional RTF high fat
9
14
1.48
0.122 0.171 8.23
11.5
0.38
Infant elemental powder
9
18
0.543 0.0169 0.0603 3.11
11.1
0.32
Adult nutritional powder low fat
10
20
0.636 0.0348 0.0587 5.47
9.23
0.27
a
HorRat = RSD/PRSD; PRSD = 2C
–0.15
(C = concentration by mass fraction).
b
Results in µg/kg powder.
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