An isocratic concurrent assay of free metabolites, 4-hydroxy-3-methoxy mandelic acid, 3-methoxy-4-hydroxy-phenylglycol, normetanephrine, metanephrine, and 5-hydroxy-indoleacetic acid in same sample of urine extract using HPLC-ECD

This paper describes a method for simultaneous extraction and concurrent quantification of metabolites of norepinepohrine (NE) and 5-hydroxytryptamine (5-HT) in human urine using an isocratic HPLC-ECD technique. These metabolites include 4-hydroxy-3-methoxy mandelic acid (VMA), 3-methoxy-4-hydroxyphenylglycol (MHPG), normetanephrine (NMTN), metanephrine (MTN), and 5-hydroxyindoleacetic acid (5-HIAA). The samples of urine were passed through preconditioned alumina-B column and washed with diethylether to remove interfering substances. Metabolites were extracted in ethylacetate.