Stability Study of LSD Under Various Storage Conditions

LSD in pooled urine is stable for up to 4 weeks at 25 degrees C in the dark, with no significant loss. At 37 degrees C, a 30% loss occurred after 4 weeks, and up to 40% at 45 degrees C. Amber glass or nontransparent polyethylene containers preserved LSD concentration under any light conditions; stability in transparent containers depended on distance from light source, wavelength, exposure time, and intensity. Prolonged heat in alkaline pH converted 10 to 15% of LSD to iso-LSD; under acidic conditions, less than 5% converted. Trace metal ions catalyzed decomposition, preventable by adding EDTA. Proper storage is essential for accurate analytical testing.

Study at a glance

Abstract

A controlled study was undertaken to determine the stability of LSD in pooled urine samples. The concentrations of LSD in urine samples were followed over time at various temperatures, in different types of storage containers, at various exposures to different wavelengths of light, and at varying pH values. LSD concentrations were measured quantitatively by the Abuscreen RIA and by HPLC using a fluorescence detection method. Good correlation was observed between the immunoassay and the fluorescent integrity of the LSD molecule. Thermostability studies were conducted in the dark with various containers. These studies demonstrated no significant loss in LSD concentration at 25 degrees C for up to 4 weeks. After 4 weeks of incubation, a 30% loss in LSD concentration at 37 degrees C and up to a 40% at 45 degrees C were observed. Urine fortified with LSD and stored in amber glass or nontransparent polyethylene containers showed no change in concentration under any light conditions. Stability of LSD in transparent containers under light was dependent on the distance between the light source and the samples, the wavelength of light, exposure time, and the intensity of light. After prolonged exposure to heat in alkaline pH conditions, 10 to 15% of the parent LSD epimerized to iso-LSD. Under acidic conditions, less than 5% of the LSD was converted to iso-LSD. We also demonstrated that trace amounts of metal ions in buffer or urine could catalyze the decomposition of LSD and that this process can be avoided by the addition of EDTA. This study demonstrates the importance of proper storage conditions of LSD in urine in order to insure proper analytical testing results over time.