A note on a simple estimation of amphetamine, methylamphetamine and ephedrine in horse urine

Abstract

A chromatographic separation of amphetamine, methylamphetamine and ephedrine from horse urine is possible on alkaline Silica Gel G plates developed with acetone‐methanol (1:3). After elution, the bases are determined colorimetrically. The intensity of the violet colour resulting from the nitration of amphetamine is measured in a Unicam SP1300 colorimeter using filter No. 1 (sensitivity 50–250 μg). The colour produced by the interaction of methylamphetamine, sodium nitro‐prusside, acetaldehyde and triethanolamine is measured at 590 mμ (sensitivity 200–2,000 μg). Ephedrine was determined by measuring the intensity of the brown colour of its dithiocarbamate at 440 mμ (sensitivity 100–900 μg).

A Review of Drug “Clearance Times” in Racehorses

“…Urinary metabolites appeared to have been undetectable after 24 hours. Using horses with aciduria, Karawya, El-Kiey, Wahba and Kozman (1968) claimed that unchanged ephedrine could be detected for only 3 hours after dosing. Chapman and Marcroft (1973d) reported 87 per cent of radioactivity from a dose of [14c]ephedrine to be excreted in the urine of a horse in 24 hours.…”