title: Determination of nucleotides in infant formula by ion-exchange liquid chromatography.
abstract: Nucleotide-supplemented infant formula has been shown to positively modify the composition of intestinal microflora, emulating the attribute of human milk. Quantification of nucleotides in infant formula is of interest because of its applicability in quality and safety assessments. There is no standard method for the analysis of nucleotides in infant formula. In the present study, ion-exchange liquid chromatography (IELC)- and centrifugal ultrafiltration (CUF)-based protocols were developed for routine determination of additive nucleotides in infant formula. Five target nucleotides, guanosine 5'-monophosphate (GMP), inosine 5'-monophosphate (IMP), uridine 5'-monophosphate (UMP), cytidine 5'-monophosphate (CMP), and adenosine 5'-monophosphate (AMP) were measured by IELC with a mobile phase of 50 mM diammonium hydrogen phosphate buffer, pH 4.0, with UV detection at 254 nm. The calibration was linear over the range 0.5-50 microg/mL; R(2) = 0.999. The calculated LOD and LOQ were 0.01-0.05 microg/mL and 0.05-0.5 microg/mL, respectively. Recovery values (spiked concentration levels: 0.5, 5, and 10 microg/mL) ranged from 85.0 +/- 1.4% to 92.3 +/- 2.1% using only CUF preparation. This was applied to measure the concentration of five nucleotides in common infant formulas.
authors.affiliation: Department of Physical and Analytical Chemistry, School of Pharmacy, Kinjo Gakuin University, 2-1723 Omori, Moriyama-ku, Nagoya, 463-8521, Japan. kinoue@kinjo-u.ac.jp
authors.forename: Koichi
authors.initials: K
authors.lastname: Inoue
authors.forename: Rutsuko
authors.initials: R
authors.lastname: Obara
authors.forename: Takashi
authors.initials: T
authors.lastname: Akiba
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Hino
authors.forename: Hisao
authors.initials: H
authors.lastname: Oka
mesh_terms: D000249:Adenosine Monophosphate / Q000032:analysis; D002852:Chromatography, Ion Exchange / Q000379:methods*; D003568:Cytidine Monophosphate / Q000032:analysis; D006157:Guanosine Monophosphate / Q000032:analysis; D006801:Humans; D041943:Infant Formula / Q000737:chemistry*; D007291:Inosine Monophosphate / Q000032:analysis; D008895:Milk, Human / Q000737:chemistry; D009711:Nucleotides / Q000032:analysis*; D011786:Quality Control; D014462:Ultrafiltration; D014542:Uridine Monophosphate / Q000032:analysis
chemical_list: D009711:Nucleotides; D007291:Inosine Monophosphate; D000249:Adenosine Monophosphate; D006157:Guanosine Monophosphate; D014542:Uridine Monophosphate; D003568:Cytidine Monophosphate