Impurities in Labeled Diethylstilbestrol: Identification of Pseudodiethylstilbestrol

Abstract

Radioactive impurities known to exist in labeled diethylstilbestrol used in tissue residue studies in cattle include at least five different compounds, one of which is identified as pseudodiethylstilbestrol.

Analysis by gas-liquid and thin-layer chromatography of residual [14C]diethylstilbestrol ear implants

“…This difference may represent a product of slow autodegradation. One distinct zone migrated between cis-and frans-DES and may correspond to the zone identified as pseudodiethylstilbestrol by Tennent et al (1976). Four zones of radioactivity migrated faster than frans-DES and these were combined.…”

“…The aqueous hexane was prepared by saturation of hexane with water. The mobile phases were similar to those used previously for DES and for estrogens (Kircher, 1967;Schuller, 1967; Jeffus and Kenner, 1972;and Tennent et al, 1976). All solvents except ethyl ether were distilled and mixed on the basis of volume.…”

“…Thirteen visible zones of radioactivity were found in this study for the first system. Only nine zones were obtained by Tennent et al (1976) who used a similar system. This inconsistency in the number of zones may be caused by factors that affect method sensitivity such as the amount of radioactivity applied to TLC plates and the length of time that X-ray film is exposed to TLC plates.…”

“…This inconsistency in the number of zones may be caused by factors that affect method sensitivity such as the amount of radioactivity applied to TLC plates and the length of time that X-ray film is exposed to TLC plates. Tennent et al (1976) did not state the amount of radioactivity applied but stated that exposure time was variable (2 to 5 days). In our laboratory, shortening the exposure time and, particularly, reducing the amount of radioactivity applied to the TLC plates reduced the number of radioactive zones that were visible in the autoradiogram.…”