4-methoxy-3-hydroxyphenylglycol as an internal standard for the determination of 3-methoxy-4-hydroxyphenyglycol in urine: results obtained in depressed patients and healthy controls.

A modification of the method developed by Dekirmenjian & Maas (1970) Anal. Biochem. 35, 113-122) is described for the determination of 3-methoxy-4-hydroxyphenylglycol in urine. The use of 4-methoxy-3-hydroxyphenylglycol as an internal standard improves the accuracy, simplicity and reproducibility. Therefore, the method is suitable for routine determination in laboratories without gas chromatography/mass spectrometry equipment. Some results obtained in depressed patients and healthy controls are presented.