Determination of 2-hydroxyphenylacetic acid (2HPAA) in urine after oral and parenteral administration of coumarin by gas-liquid chromatography with flame-ionization detection

The urinary excretion of 2-hydroxyphenylacetic acid (2HPAA) was studied in human volunteers after oral and parenteral doses of coumarin. The presence of 2HPAA in the urine was confirmed by gas chromatography mass spectroscopy (GC MS). Mass spectra of reference material and samples are presented. The determination of 2HPAA was carried out by GC with flame-ionization detection. Prior to analysis samples were extracted into ethyl ether and the analytes were derivatized with trimethylphenylammonium hydroxide. A calibration range from 0.3 to 150 mu g ml(-1) was established using 3-hydroxyphenyl acetic acid (3HPAA) as an internal standard. On average less than 10% of the coumarin administered were excreted into the urine in the form of 2HPAA. (C) 1998 Elsevier Science B.V. Al rights reserved.