Ortuño J., González M.L., Verstraete A.G.^*, Ventura R., Segura J., de la Torre R.

Abuse Research Unit, Institut Municipal d'Investigació Mèdica, UAB, 08003 Barcelona, Spain
^* Laboratory of Clinical Biology - Toxicology, University Hospital, De Pintelaan 185, B-9000 Gent, Belgium

Lysergic acid diethylamide (LSD) is a potent psychoactive drug with hallucinogenic effects. The low dose used (20-120 µg) and the extensive metabolism difficults its analytical detection in biological material.
Iso-LSD, a diasteromer of LSD without psychoactivity, sometimes appear as a major constituent of illicit LSD preparations. The availability of some new immunoassays facilitate detection of LSD consumption but also rises the need of the availability of reliable confirmatory analytical techniques. The procedure developed use a solid reversed phase with cationic exchange (Bond Elut Certify) columns to extract LSD and the Internal standard (LSD-D3) from urine. The trimethylsilyl derivatives are separated with a 5% phenylmethylsilicone capillary column (12m, 0.22mm i.d., 0.33µm film thickness) with an helium flow of 0.8 mL/min. Injection was made in splitless mode with the oven temperature programmed from 150ºC to 300ºC. A selective ion monitoring (SIM) of 5 ions (m/z 395,293,268,398 and 296) was used for the detection of LSD and LSD-D3. Recoveries for both compounds were >85%. Intra-run precision and accuracy were 6.9 and 5.8 % (at 200 pg/mL). The method shows linearity over the concentration range 200-2000 p/mL (r2=0.9960). Limit of detection was calculated to be as low as 44 pg/mL. This method shows good specificity and sensitivity to confirm the presence of LSD and iso-LSD in urine