[Determination of 5-hydroxytryptamine in plasma by nanofiber solid phase extraction-high performance liquid chromatography].

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 12 000 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 degrees C 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 microg/L with the correlation coefficient (r2) of 0.9996. The limit of detection (S/N = 3) was 1 microg/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.