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

- Simultaneous separation of nucleosides and nucleotide mono- di- and tri-phosphates.
- Hexafluoro-2-propanol as a highly efficient additive in CE-MS is proposed.
- Sample treatment based in ultracentrifugation compatible with CE-MS.
- Determination of nucleosides and nucleotides in baby food samples.

The present work describes a method for the simultaneous determination of unmodified nucleosides and nucleotide mono-, di- and tri-phosphates by capillary electrophoresis coupled to mass spectrometry (CE-MS). The use of hexafluoro-2-propanol (HFIP) in the separation medium, and as an additive to the sheath liquid of the electrospray interface (ESI), generated a highly efficient and sensitive method. Instrumental limits of detection in the range of 14-53 ng mL−1 for nucleosides and 7-23, 20-49 and 64-124 ng mL−1 for nucleotide mono-, di-, and tri-phosphates, respectively, were found. Sample treatment involved diluting an aliquot of baby food with ultra-high quality water and applying centrifugation-assisted ultrafiltration (CUF). The proposed method was validated and used to analyse a variety of baby food samples (16 in total) such as fish, meat, fruits, and baby dairy desserts that may endogenously contain these analytes.