[Rapid analysis of tryptophan in serum by high performance liquid chromatography with fluorescence detection]

A sensitive, rapid and specific method for the determination of tryptophan(Trp) in serum by high performance liquid chromatography with fluorescence detection (HPLC-FLD) has been established. Serum sample was precipitated by 5% perchloric acid solution and centrifuged to remove protein and then assayed by HPLC-FLD. The operating conditions were Nova-Pak C18 column (3.9 mm i.d x 150 mm, 4 microns), 5 mmol/L KH2PO4 as the mobile phase at a flow rate of 1.0 mL/min. The fluorescence detector was operated at lambda ex 254 nm and lambda em 338 nm. The method was proved to be linear in the range of 0.49 mumol/L-490.00 mumol/L with a regression coefficient of 0.9999. The minimum detection limit was 0.10 mumol/L. The recoveries were 97.2%-98.6%. The intra-batch and inter-batch RSDs were 2.0% and 3.2% respectively. The detection time of serum Trp was within 5 min after injection. The results suggest that this method is simple, fast, accurate and convenient.