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Single Laboratory Validation – AOAC First Action Method 2012.22 Vitamin C in Infant Formula and Adult/Pediatric
Nutritional Formula by UPLC-UV
Date of Issue: February 14
th
, 2013
RDLS-RD130018
E.Campos Giménez (NRC/QS, Lausanne)
Page 4
Materials and Methods,
Continued
Results
reporting
All results were reported in mg ascorbic acid/100 g expressed in product “as is”
for RTF (ready-to-feed) products, or as “reconstituted powder” for powder
samples. Results were compared with Standard Method Performance
Requirements (SMPR) (Attachment 3).
Statistical
analysis/
calculations
Standard deviation of repeatability (S
r
) and Standard deviation of
intermediate reproducibility (S
iR
)
were calculated from duplicate analysis on
7 different days using classic statistics:
Where:
- n is the number of duplicate determinations (6)
- x
i1
and x
i2
are the two single results with i going from 1 to n
- SD(b) is the standard deviation between the means of duplicates
- SD(r ) is the standard deviation of repeatability
Recovery rates (%)
were calculated as:
Where:
- C
spiked
is the concentration measured in the spiked sample
- C
native
is the concentration measured in the non fortified sample (overall
mean of unspiked samples)
- C
added
is the concentration of analyte added
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VitC-03/2012.22
For ERP Use Only
DO NOT DISTRIBUTE
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