Determination of histidine in human serum and urine by cation exchange chromatography coupled to selective on-line post column derivatization

• Published in: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Vol. 1173; p. 122697
• Main Authors: Stampina, Eirini, Tsiasioti, Apostolia, Klimatsaki, Kalliopi, Zacharis, Constantinos K., Tzanavaras, Paraskevas D.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 30.05.2021
• Subjects: Cation exchange chromatography; Histidine; Human serum; Human urine; Post column derivatization; Human serum; Histidine; Post column derivatization; Cation exchange chromatography; Human urine
• ISSN: 1570-0232; 1873-376X
• DOI: 10.1016/j.jchromb.2021.122697

•Selective micromolar determination of Histidine in human serum and urine.•Post column reaction with o-phthalaldehyde without nucleophilic reagent.•Unique reaction mechanism offers selectivity against endogenous matrix compounds.•Direct injection following protein precipitation / dilution.•Robust cation exchange separation coupled to post column derivatization. A reliable and highly selective method for the determination of histidine in human serum and urine is described. Histidine was separated from the matrix by cation exchange chromatography and detected selectively using on-line post column derivatization and fluorimetric detection. Unique reaction of histidine with o-phthalaldehyde in the absence of nucleophilic compounds offered specific detection in the complex biological substrate. Linearity was obeyed in the range of 0.5 – 25 μmol L-1 with a limit of detection of 0.160 μmol L-1. The absence of matrix effect (<5%) enabled the processing of real samples after minimal pretreatment. Endogenous histidine has been determined in human serum in the range of 78 – 119 μmol L-1 and random human urine in the range of 266 – 2034 μmol L-1. The percent recoveries were satisfactory in all cases, ranging between 89 and 114%.