title: The assay of 4-hydroxy-3-methoxymandelic acid in urine by HPLC with electrochemical detection using bonded-phase silica sorbents for rapid, simple and selective extraction.
abstract: A method is reported for the determination of 4-hydroxy-3-methoxymandelic acid (HMMA) by HPLC with electrochemical detection. The preparation of sample prior to HPLC has been studied and an efficient and selective extraction procedure described. Bonded-phase silica extraction columns and a vacuum manifold were used for the simple and rapid processing of batches of urine samples. Combining a reverse-phase C18 and an anion exchange column ensures selective isolation of HMMA. This simplified greatly the subsequent chromatography. The method was combined into a simple scheme for the routine analysis of urine HMMA, catecholamines and 5-hydroxyindole-3-acetic acid. The HPLC was standardised such that a single mobile phase was used with minor modification for each of the assays.
mesh_terms: D002845:Chromatography; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004563:Electrochemistry; D005069:Evaluation Studies as Topic; D006801:Humans; D011786:Quality Control; D012015:Reference Standards; D012822:Silicon Dioxide; D014642:Vanilmandelic Acid / Q000592:standards / Q000652:urine*
chemical_list: D014642:Vanilmandelic Acid; D012822:Silicon Dioxide