Determination of dopamine, epinephrine, and norepinephrine by open-tubular capillary electrochromatography using graphene oxide molecularly imprinted polymers as the stationary phase

A novel capillary electrochromatography method was developed for the determination of dopamine (DA), epinephrine (EP), and norepinephrine (NE) by using a graphene oxide (GO) molecularly imprinted polymers (MIPs) coated capillary. In this article, GO was introduced as supporting matrix to synthesize MIPs in the presence of DA as template molecule. Then GO MIPs were used as the stationary phase in electrochromatography for the determination of DA, EP, and NE. The separation of these three analytes was achieved under the optimal conditions with a satisfactory correlation coefficients (R-2) > 0.9957 in the range of 5.0-200.0 mu g/mL for EP and NE, and 20.0-200.0 mu g/mL for DA, respectively. The RSDs for the determination of three analytes were <6.19%, and the detection limits were 1.25 mu g/mL for EP and NE, and 10.0 mu g/mL for DA, respectively. Finally, this method was used for the determination of DA, EP, and NE in human serum and DA hydrochloride injection.