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Dual Lab Validation of a Method for the Determination of Fructans in Infant
Formula & Adult Nutritionals /
25 Jul 2016
14
2.3.2
Precision
All samples from the SPIFAN kit were analysed in duplicate on a single day, and six of the samples
were found to contain fructans; The Placebo Child Formula Powder and the following fortified
products: Toddler Formula Powder Milk Based, Infant Formula Powder Milk Based, Child Formula
Powder, Infant Formula FOS/GOS Based, Adult Nutritional RTF High Fat, Milk Powder with Prebiotics.
In addition, two Nestlé samples were also analysed giving a total of 8 matrices for the precision study.
Each of the fructan‐containing samples from the SPIFAN kit were reconstituted as instructed and
analysed in duplicate, on at least six different days, using 2 different instruments (same model) and
2 different columns (same stationary phase and manufacturer, but different lot). At the same time
the two Nestlé samples were also analysed (without reconstitution). SD(r) and SD(iR) were calculated
from the data obtained using the equations below:‐
SD(r)
n2
x x
n
SD
r SD
n
1i
2
2i
1i
n
1i
2
i
SD(iR)
r SD
2
1 b SD iR SD
2
2
Where:
n is the number of (single or duplicate) determinations
x
i
is the individual result within the set of single determinations with i going from 1 to n ;
x
i1
and x
i2
are the two results within the set of duplicate determination with i going from 1 to n ;
SD(b) is the standard deviation between the means of duplicates
2.3.3 Accuracy
Six matrices were selected that covered both infant formula and adult nutritionals (see Table 4 for
details). They were analysed in duplicate on three different days by two different operators on two
different instruments without spiking (level 0) and spiked with Orafti HP, Orafti P95 or Nutraflora
P95, each at one of three levels (Table 4). The fructan powders used for spiking were separately
analysed using method AOAC 997.08 [1] to confirm their fructan content.
VALIDATION REPORT
FOR ERP USE ONLY
DO NOT DISTRIBUTE