Reproducibility
51
The standard deviation or relative standard deviation calculated from among-
52
laboratory data. Expressed as the reproducibility relative standard deviation
53
(SD
R
); or % reproducibility relative standard deviation (% RSD
R
).
54
55
56
57
4.
Method Performance Requirements:
58
59
Analytical range
5 - 200*
Limit of Quantitation (LOQ)
≤
5
*
Recovery
5-25
80-120%
26-200
90-110%
Repeatability (RSD
r
)
5-25
≤
8%
26-200
≤
5%
Reproducibility (RSD
R
)
5-25
≤
15%
26-200
≤
10%
Concentrations apply to: a) ‘ready
-to-
feed” liquids “as is”; b) re
-
constituted powders (25 g into 200 g of deionized water); and c)
liquid concentrates diluted 1:1 by weight with deionized water.
*
μ
g /100 g reconstituted final product.
60
61
5.
System suitability tests and/or analytical quality control:
62
Suitable methods will include blank check samples, and check standards at the
63
lowest point and midrange point of the analytical range.
64
65
6.
Reference Material(s)
: Neither NIST nor IRRM produce an CRM for fluoride in infant
66
formula. The fluoride content of SRM 1849a has not been determined (as of
67
11/20/2013).
68
69
70
7.
Validation Guidance
:
71
Recommended level of validation:
Official Methods of Analysis
SM
.
72
73
8.
Maximum Time-To-Result
: No maximum time.
74
