HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR RAPID AND HIGHLY SENSITIVE DETERMINATION OF HISTIDINE USING POSTCOLUMN FLUORESCENCE DETECTION WITH O-PHTHALDIALDEHYDE

A high-performance liquid chromatographic method was developed for the rapid and sensitive determination of histidine. The method is based o n separation by reversed-phase ion-pair chromatography followed by hig hly selective fluorescence derivatization of histidine with o-phthaldi aldehyde. A linear calibration curve was obtained over the range of 0. 25-200 pmol per injection (10 mu l) with the coefficient of variation of 0.9% at 2 pmol (n = 10) and with the detection limit (S/N = 8) of 2 5 fmol. The method was applicable to the assay of histidine in human s erum. Serum histidine values obtained by the present method were in go od agreement with values obtained with an amino acid analyzer. (C) 199 8 Elsevier Science B.V. All rights reserved.