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biotin. The report does not show these chromatograms nor clarify if the “response” was attributed to
(endogenous) biotin or was an interference.
-
Method Optimization:
•
Performance Characteristics:
Analytical Range:
•
The method describes the processing of samples with biotin content over the entire concentration
range stated in the SMPR (0.1 – 150 mcg/100g as fed)
•
In practice, the concentration encountered in the SLV using the SPIFAN sample set was ~1.5 – 65
reconstituted.
LOQ:
•
The SMPR LoQ (0.1 mcg/100g reconstituted) is achieved at the lowest standard curve concentration
using the typical sample weight specified in the method for this concentration of analyte.
Accuracy/Recovery:
SMPR:
0.1
– 1 mcg/100g reconstituted: 80 - 120%
> 1 mcg/100g reconstituted: 90 – 110%
•
Spike and recovery: Four placebo samples (Child Formula, Infant Elemental, Adult RTF High Fat, IF Milk
RTF) were spiked at +50% and +150% of typical target, 3 days in duplicate, with recoveries meeting the
SMPR requirements ranging from 95.2% – 100%. One fortified sample (Adult RTF High Protein) was
spiked similarly and showed recovery of 96.7% - 104%, also meeting the SMPR requirement. (Table 3)
•
SRM 1849a: the sample was analyzed on 6 different days; the results (range 196.5 – 200.0 mcg/100g as
is) were all well within the Certified Mass Fraction range (199 ± 13 mcg/100g as is). (Table 2)
Precision (RSD
r
):
SMPR:
0.2
– 1 mcg/100g reconstituted: ≤ 8%
> 1 mcg/100g reconstituted: ≤ 6%
Reproducibility (RSD
R
):
SMPR:
0.1
– 1 mcg/100g reconstituted: ≤ 16%
> 1 mcg/100g reconstituted: ≤ 12%
RSD
IR
was characterized by duplicate analysis of the 12 fortified SPIFAN samples across 6 days (2
analysts, 2 instruments). All values were below 3.2%. Although they were not calculated
individually, none of the within day precision values appeared to be greater than this value. The
method could likely meet the SMPR requirements if extended to MLT. (Table 4)
3/2017: The MLT consisted of 12 laboratories from 10 different countries. Three laboratories only
reported results for the practice samples. One of the remaining laboratories produced results