Method:Pre-column derivatization with 2,4-dinitrobenzene(DNFB). The mobile phase was a solution of acetonitrile-triethyamine(pH3. 6) (60 : 40). The detection wavelength of 365nm was used.

• 方法:用2；4-二硝基氟苯作柱前衍生剂；乙腈-三乙胺溶液(pH3.；6)(60:40)为流动相；检测波长为365nm。