Collaborative Study Report: Method 2011.20 Nucleotides by HPLC-UV
Page 2
Summary
A multi-laboratory collaborative study of AOAC First Action 2011.20, an HPLC-UV method for the analysis of
nucleotides; uridine 5′-monophosphate (UMP), inosine 5′-monophosphate (IMP), adenosine
5′-monophosphate (AMP), guanosine 5′-monophosphate (GMP), and cytidine 5′-monophosphate (CMP), in
infant formula was undertaken. Twelve laboratories participated in the analysis of blind duplicates of a soy-
based infant formula containing endogenous nucleotide levels <0.54 mg hg
-1
and duplicate pairs of 5
nucleotide supplemented formulas containing concentrations ranging from at 4.4–13.1 mg hg
-1
for CMP,
2.7–4.6 mg hg
-1
for UMP, 0.9–1.8 mg hg
-1
for GMP, 1.5–3.9 mg hg
-1
for IMP, and 3.1–5.2 mg hg
-1
for AMP.
RSD
r
values obtained ranged from 1.1–2.7% for CMP, 1.4–5.4% for UMP, 1.6–3.9% for GMP, 1.1–1.8% for
IMP, and 1.1–3.9% for AMP. RSD
R
values obtained ranged from 7.1–8.7% for CMP, 7.9–9.0% for UMP,
2.8–7.7% for GMP, 5.5–10.3% for IMP, and 3.0–7.8% for AMP. For all nucleotide supplemented infant
formulas, the repeatability and reproducibility are within limits set in the Nucleotides SMPR (3). Acceptable
reproducibility was also demonstrated with HorRat values for the method ranging from 0.3–1.0. On the
basis of the results of this study, it is recommended that AOAC First Action 2011.20 be endorsed as Final
Action for the determination of adenosine 5′-monophosphate (AMP), cytidine 5′-monophosphate (CMP),
guanosine 5′-monophosphate (GMP), inosine 5′-monophosphate (IMP), and uridine 5′-monophosphate
(UMP) in infant formula and be entitled: AOAC Official Method 2011.20 Nucleotides in Infant Formula.
