2
Variation arising when all efforts are made to keep conditions constant by using the same
48
instrument and operator, and repeating during a short time period. Expressed as the
49
repeatability standard deviation (SD
r
); or % repeatability relative standard deviation
50
(%RSD
r
).
51
52
Reproducibility
53
The standard deviation or relative standard deviation calculated from among-laboratory
54
data. Expressed as the reproducibility relative standard deviation (SD
R
); or % reproducibility
55
relative standard deviation (% RSD
R
).
56
57
Vitamin B
1
(Thiamin)
58
2-[3-[(4-Amino-2-methyl-pyrimidin-5-yl)methyl]-4-methyl-thiazol-5-yl] ethanol. CAS
59
number: 59-43-8. See Figure 1.
60
61
62
Figure 1: Chemical structure of
vitamin B
1
(
thiamine).
63
64
65
66
4.
Method Performance Requirements:
67
68
Analytical range
20 – 250*
Limit of Quantitation (LOQ)
≤ 20*
Accuracy
± 20%
Repeatability (RSD
r
)
≤ 14%
Reproducibility (RSD
R
)
≤ 20%
Concentrations apply to: a) ‘ready-to-feed” liquids “as is”; b) re-
constituted powders (25 g into 200 g of water); and c) liquid
concentrates diluted 1:1 by weight.
*μg /100 g reconstituted final product.
69
70
71
5.
System suitability tests and/or analytical quality control:
72
Suitable methods will include blank check samples, and check standards at the lowest point
73
and midrange point of the analytical range.
74
75
6. Reference Material(s):
76
NIST Standard Reference Material
®
1849a; Infant/Adult Nutritional Formula or equivalent.
77
The SRM is a milk-based, hybrid infant/adult nutritional powder prepared by a manufacturer
78
of infant formula and adult nutritional products. A unit of SRM 1849 consists of 10 packets,
79
each containing approximately 10 g of material. Certified value of NIST1849a is 12.57
±
0.98
80
mg/Kg of vitamin B
1
(thiamin).
81
