Validated Ultraviolet High-Performance Liquid Chromatography Method for Post-mortem 5-Hydroxy-indoleacetic Acid Measurement in Human Cerebrospinal Fluid

Abstract Objective  The objective of this study was to develop an ultraviolet high-performance liquid chromatography (UV-HPLC) method for the measurement of 5-hydroxyindoleacetic acid (5-HIAA) in human cerebrospinal fluid (CSF) as a potential biomarker for neurological and psychiatric illnesses, including depressive disorders with suicidal behavior. Methods  The study utilized CSF samples from individuals brought for medicolegal autopsy. The 5-HIAA concentration was measured using a UV-HPLC method with three mobile-phase solvents. The most effective mobile phase solvent was then used to measure 5-HIAA in the CSF samples. Materials  The materials used in the study included CSF samples obtained from individuals brought for medico-legal autopsy, UV-HPLC equipment, and mobile phase solvents, including 5-hydroxyindole-3-acetic acid (Merck/sigma), acetonitrile, concentrated formic acid, concentrated acetic acid, methanol, and phosphoric acid. Statistical Analysis  This was done using R Studio (version 4.2.0). Results  The study found that the UV-HPLC method utilizing formic acid (0.05–0.1%): acetonitrile in a 1:9 as mobile phase was the most effective for measuring 5-HIAA in human CSF. The method exhibited excellent linearity, accuracy, and precision. Conclusion  The study concludes that the developed UV-HPLC method is reliable and effective for measuring 5-HIAA in human CSF. Measuring 5-HIAA levels in CSF can serve as a potential biomarker for neurological and psychiatric illnesses, including depressive disorders with suicidal behavior. This method is promising for clinical and forensic practice to diagnose suicidal cases. Further research is needed to determine the clinical significance of these findings and the potential for broader application in psychiatry. This article helps to give a practical, cost-effective methodology to detect CSF 5-HIAA.