Separation and determination of urinary homovanillic acid and iso-homovanillic acid by gas-liquid chromatography and electron capture detection.

Abstract Separation and detection of homovanillic acid (HVA) and 3-hydroxy-4-methoxyphenylacetic acid (iso-HVA) were achieved by gas-liquid chromatography and electron capture detection. Urines from 20 normal subjects, 18 children with neuroblastoma, and 7 patients with Parkinson's disease before and during l-dopa treatment were evaluated for both HVA and iso-HVA. The mean normal value obtained for HVA was 3.72 μg per milligram creatinine while that for iso-HVA was 0.28 μg per milligram creatinine. Increased HVA and iso-HVA were observed in patients with neuroblastoma while untreated Parkinson's disease patients had slightly elevated levels of HVA and markedly diminished iso-HVA levels. Although both compounds increased after L-dopa therapy, the elevation of iso-HVA was more marked than that of HVA.