Hypercrosslinked strong cation-exchange polymers for selective extraction of serum purine metabolites associated with gout

In this study, hypercrosslinked strong cation-exchange polymer resins (HXLPP-SCX) were synthesized and employed as selective sorbents for the solid-phase extraction (SPE) of basic purine metabolites associated with gout. The HXLPP-SCX material was prepared based on hypercrosslinking reactions and sulfonated with concentrated H 2 SO 4 . This synthetic procedure is facile and efficient without using highly toxic reagent. The resulting resins were characterized in the form of monodisperse microspheres (mean diameters of 3‒5   μm) with narrow pore size (2.1   nm) and relatively high specific surface areas (801   m 2 /g). The polymers also possess high ion-exchange capacity (IEC, 2.22   mmol/g) and good adsorption and selectivity performances for basic compounds. The resins used as SPE sorbents permit the selective enrichment of three pivotal purine metabolites (hypoxanthine, xanthine and inosine) in human serum followed by HPLC analysis. Method validation including linearity range, sensitivity, accuracy and reproducibility were evaluated. This method was exemplarily applied in the analysis of serum purines in gout patients and healthy controls. The present results demonstrate a promising potential of this HXLPP-SCX material for the clinical sample pretreatment.