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FOR EXPERT REVIEW PANEL USE ONLY
NOT FOR DISTRIBUTION
3
The linear calibration range from 0.25 to 50 pmol/μL was established for all amino acids except
Cystine (corresponds to average concentrations between 2 and 820 mg/100 g, depending an amino acid).
For Cystine linear calibration range was between 0.25 – 10 pmole/uL.
It was determined that about 2 % of measured values in SPIFAN II kit were above the calibration
range.
The linear range doesn’t meet SMPR requirements
LOQ:
Was determined as 2.5 mg/100 g. This doesn’t meet SPMR requirements of 0.4 mg/100 g but based
on actual amino acids concentrations found in the matrices this level seems to be sufficient for the scope of
analyzing amino acids in baby formula and adult nutritionals.
Accuracy/Recovery:
Accuracy was evaluated by doing spike-recoveries studies on SPIFAN matrices as well as analyzing
NIST standard reference material 1849a and comparing the results with CofA.
For SRM 1849a results for 3 amino acids (Aspartic Acid, Lysine and Tyrosine) fell outside of certified
range.
Spike recoveries showed that recoveries for 23 % of analyzed amino acids didn’t meet SMPR. The
authors don’t described what spike level was used
Precision (RSD
r
):
Repeatability data for majority of amino acids in all the matrices met SMPR requirements. Only a
few were outside the range but still were very close to specifications and none exceeded 4%.
Reproducibility (RSD
R
):
Intermediate reproducibility was determined for all SPIFAN II matrices. Intermediate reproducibility
for majority (67%) of amino acids didn’t meet SMPR requirements with considerable number of values
being well above the highest acceptance criteria of 5%. Intermediate reproducibility for many amino acids
was higher than 10 %
•
System suitability:
Notes about performance of the system are included in the method