A validated method for the determination of nucleotides in infant formulas by capillary electrophoresis coupled to mass spectrometry

Abstract

In this work CE-ESI-MS is proposed for the identification and simultaneous quantification of several ribonucleotide 5'-monophosphates in infant formula (IF) samples. The target compounds were adenosine 5'-monophosphate, cytidine 5'-monophosphate, guanosine 5'-monophosphate, uridine 5'-monophosphate, and inosine 5'-monophosphate. To our knowledge, the application of CE for the determination of these bioactive compounds in IFs has not yet been described. Optimization of the composition of the electrophoretic separation buffer and -mainly- the injection medium was carried out with a view to obtaining the best sensitivity and separation efficiency for the CE-MS coupling. Different sample treatments were assayed and one based on centrifugal ultrafiltration proved to be the simplest and most compatible with CE separation of the analytes and their ionization by the electrospray source. The whole optimized method (centrifugal ultrafiltration treatment prior to CE-MS) was validated according to the 2002/657/EC decision, obtaining a reliable and robust CE-MS method to determine these compounds in IF samples, with LODs between 0.8 and 1.8 μg/g (S/N = 3) and recoveries in the 90-106% range.

Rapid determination of nucleotides in infant formula by means of nano‐liquid chromatography

“…A linear trend was obtained up to 60 s (about 450 nL of volume injected), while broaden peaks were obtained with 80 s. The best injection conditions showed LODs of 0.25 μg/mL for all the studied compounds. The values found were higher than those published in some works performed with HPLC and CE‐MS but they were in accord with the sensitivity requirements for nucleotides analysis in IF samples.…”

“…For the analysis of those highly polar compounds, CE has reported as a valuable alternative separation technique to HPLC, offering the advantage to determine nucleotides in a wide range of pH, in short analysis time, and with high efficiency .…”

Recent advances in the application of capillary electromigration methods for food analysis and Foodomics

“…CE‐MS conditions: BGE, 30 mM ammonium formate‐ammonia medium (pH 9.6); separation voltage, +30 kV; capillary temperature, 25°C; sheath liquid, 50:50, v/v isopropanol:UHQ water mixture; flow rate,1.00 mL/min, and negative ion ESI‐MS mode. Redrawn from with permission from Wiley‐VCH.…”

Capillary electrophoresis coupled to mass spectrometry employing hexafluoro-2-propanol for the determination of nucleosides and nucleotide mono-, di- and tri-phosphates in baby foods

“…), centrifugal ultrafiltration (CUF) devices and the non-thermostated centrifuge used have been described in a previous paper (Rodríguez-Gonzalo et al, 2014).…”

“…Regarding CE, methods have been described for the determination of nucleosides and nucleotides in food materials (Chen et al, 2010;Rodríguez-Gonzalo, Domínguez-Álvarez, Mateos-Vivas, García-Gómez, & Carabias-Martínez, 2014;Mateos-Vivas, Rodríguez-Gonzalo, Domínguez-Álvarez, et al, 2015). Soga et al (2007) have proposed a CE-MS method for the determination of three nucleotide mono-, di-and tri-phosphates (NMPs, NDPs, NTPs), among other analytes employing a common fused silica CE capillary.…”