Abstract: 1. Key Laboratory of Child Development and Learning Science (Ministry of Education), Southeast University, Nanjing 210096, China; 2. Research Institute of Southeast University in Suzhou, Suzhou Key Laboratory of Environment and Biosafety, Suzhou 215123, China) Abstract: A novel packed-nanofiber solid phase extraction coupled with high performance liquid chromatography-electrochemical detection (HPLC-ECD) method was established for the determination of 5-hydroxytryptamine (5-HT) in plasma. A 10% (v/v) HClO4 solution was used to precipitate the protein in plasma samples. After homogenizing for 1 min and centrifuging for 10 min at 12000 r/min, the supernatant was adjusted to pH 8.5 with 0.1 mol/L sodium tetraphenylborate and then derivatized with o-phthalaldehyde (OPA) solution at 30 ℃ for 4 min. The solution was then purified and preconcentrated by the packed-nanofiber solid phase extraction column, in which methanol was used as the eluent. The analyte was analyzed by HPLC-ECD. The chromatographic separation was achieved on a Shimadzu C18 column with pH 5.4 0.05 mol/L phosphate buffer solution (containing 0.25 mmol/L ethylene diamine tetraacetic acid)-methanol (60:40, v/v) as mobile phase. The linear range was 5~500 μg/L with the correlation coefficient (r2) of 0.9996. The limit of detection (S/N=3) was 1 μg/L. And the spiked recoveries were in the range of 95.6%~101.4% with the relative standard deviations (RSDs) of intra-day and inter-day assays below 5% (n=3). On the basis of the advantages of simplicity, high sensitivity and good reproducibility, this method can be used for the determination of 5-HT in human plasma.

Key words: 5-hydroxytryptamine, high performance liquid chromatography (HPLC), plasma, solid phase extraction, nanofibers