Sorption-spectrophotometric Determination of Catecholamines in Urine and Blood Plasma Using Hypercrosslinked Polystyrene and Gold Nanorods
The possibility of combining solid-phase extraction of natural catecholamines (epinephrine, norepinephrine, and dopamine) on a microcolumn filled with hypercrosslinked polystyrene with their subsequent spectrophotometric or solid-phase spectroscopic determination in the eluate using gold nanorods or their nanocomposites with polyurethane foam was studied. The desorption of catecholamines from hypercross-linked polystyrene by various eluents was examined. Quantitative elution of all three catecholamines is achieved using 6 M acetic acid. Moreover, this eluent is compatible with the indicated determination variants. The features of dynamic sorption of catecholamines from urine and blood serum are described. It allows to reduce the influence of matrix components and increase sensitivity of the analysis due to preconcentration. The average enrichment factor is 10–56 with sample volumes of 10–300 ml. The developed methods allow to determine catecholamines in urine at the level of their normal content.