Selective extraction of catecholamines by packed fiber solid-phase using composite nanofibers composing of polymeric crown ether with polystyrene.

For the first time, electrospun composite nanofibers comprising polymeric crown ether with polystyrene (PCE-PS) have been used for the selective extraction of catecholamines - dopamine (DA), norepinephrine (NE) and epinephrine (E) - prior to their analysis by high-performance liquid chromatography-electrochemical detection. Using a minicartridge packed with PCE-PS composite nanofibers, the target compounds were extracted effectively from urine samples to which diphenylborinic acid 2-aminoethyl ester was added as a complexing reagent. The extracted catecholamines could be liberated from the fiber by the addition of acetic acid. A good linearity was observed for catecholamines in the range of 2.0-200 ng mL(-1) (NE, E and DA). The detection limits of catecholamines (signal-to-noise ratio = 3) were 0.5 ng mL(-1) (NE), 0.2 ng mL(-1) (E) and 0.2 ng mL(-1) (DA), respectively. Under the optimized conditions, the absolute recoveries of the above three catecholamines were 90.6% (NE), 88.5% (E) and 94.5% (DA). The repeatability of extraction performance was from 5.4 to 9.2% (expressed as relative standard deviation). Our results indicate that the proposed method could be used for the determination of NE, E and DA in urine.