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Dual Lab Validation of a Method for the Determination of Fructans in Infant
Formula & Adult Nutritionals /
25 Jul 2016
36
c.
LOD and LOQ
For the determination of the LOD and LOQ the SPIFAN SLV guidandance [5] demands for 10
independent analyses of a blank sample or 10 independent analysis of an at low level spiked blank
sample.
In this study one no fructan containing samples will be selected from the 19 samples in the SPIFAN SLV
sample kit. After reconstitution of this samples, it will be spiked with a pure fructan ingredient at a
concentration level slightly higher than the required LOQ level in the SMPR 2014.02 of ≤0.03%. The
fructan content in this spiked sample will be measured in 10‐fold applying repeatability conditions.
The average fructan content and the fructan standard deviation (SD
r
) are calculated by applying the
following equations:
x
i
= individual result of the measured fructan content in the spiked sample
= average fructan content
SD
r
= repeatability standard deviation in the average fructan content
Then the LOD and LOQ will be calculated as:
LOD = 3 x SD
r
LOQ = 10 x SD
r
d.
Precision
The SPIFAN SLV guidance [5] requires that “all samples selected for precision studies will be analyzed
in duplicate on each of 6 days using multiple analysts and instruments as practical for the different
days”. Fresh reagents and working standards are used each day. The obtained results are used to
calculate the repeatability and reproducibility for each sample.
About 6 different fructan containing samples will be selected for this part of the investigation.
The repeatability standard deviation (SD
r
) and reproducibility (SD
R
) will be calculated from the
obtained data.
Of each sample the SD
r
and RSD
r
are calculated by pooling the six SD’s and RSD’s of the six duplicate
analyzes of that sample.
For calculating the SD
R
and RSD
R
the analytical data of all six days are put together, and then the
average, SD
R
and RSD
R
are calculated.
)1 /( )
(
2
1
n x x
SD
i
r
x
VALIDATION REPORT
FOR ERP USE ONLY
DO NOT DISTRIBUTE