The aim of the study was the synthesis and application of novel adsorbents for the extraction of nucleotides from dietary supplements. Three different adsorbents modified with a silane containing two amine groups and various dicarboxylic acids were synthesized and characterized using various instrumental techniques. Next, different solvents were tested for their adsorption and desorption of five nucleotides. The results showed that the efficiency of both processes depends on the conditions used and the type of dicarboxylic acid bound to the surface of the adsorbent. The best results were obtained for succinic acid. The most effective adsorption occurred for water acidified with acetic acid to pH 4.5, while the highest recoveries (85-102%) with high reproducibility were obtained for 10 mM ammonium acetate at pH 9. The nucleotide extraction was performed simply by changing the charge at the adsorbent surface, providing the possibility of electrostatic attraction and repulsion between the adsorbent and nucleotides. Moreover, the sorption capacity of the obtained materials was also determined, which was essential for their use in extracting nucleotides from real samples by dispersive extrusion to the solid phase. The new adsorbents and the developed extraction method were successfully applied to isolate nucleotides from two different dietary supplements with different compositions (one of them with yeast strains). The method is simple and reproducible; no organic solvents or high-concentration inorganic salts are used (it is environmentally friendly). The entire process is performed in one centrifuge tube and is cheaper compared with methods used so far.
Keywords: dietary supplements; dispersive solid-phase extraction; electrostatic interactions; new adsorbents; nucleotides.