Potassium permanganate used to eliminate interference with the Porter-Silber reaction in the butanol extraction method for determination of urinary 17-hydroxycorticosteroids.

We describe a simple, rapid, and less interference-susceptible method for using the Porter-Silber reaction for determination of urinary 17-hydroxycorticosteroids. The procedure is based on butanol extraction of the steroids after the urine sample is treated with potassium permanganate and sodium bisulfite. These treatments, together with an additional acid- and alkali-washing of the extract, could eliminate most of the substances in urine that interfere with the Porter-Silber reactions. Values so obtained correlated well (r = 0.95) with those by Furuya's method in which beta-glucuronidase is used. Our method may be useful and suitable for a screening test of adrenocortical and pituitary functions.