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Helga Köhler

3 papers in the library · 75 citations · publishing 2002-2015

Papers

Determination of psilocin, bufotenine, LSD and its metabolites in serum, plasma and urine by SPE-LC-MS/MS.

International journal of legal medicine May 1, 2013 Rafaela Martin, Jennifer Schürenkamp, Angela Gasse et al. 55 citations

A new laboratory method using liquid chromatography and mass spectrometry reliably measures the hallucinogenic drugs psilocin, bufotenine, and LSD along with their breakdown products in blood and urine. The procedure protects unstable compounds by adding vitamin C, drying with nitrogen, and blocking light. It recovers at least 86% of each drug, shows no significant interference from other substances, and produces consistent results with low variability. Processed samples remain stable for at least two days. The method was successfully tested on real patient samples.

Analysis of psilocin, bufotenine and LSD in hair.

Journal of analytical toxicology March 1, 2015 Rafaela Martin, Jennifer Schürenkamp, Angela Gasse et al. 13 citations

A method extracts the hallucinogens psilocin, bufotenine, LSD, and related compounds (iso-LSD, nor-LSD, O-H-LSD) from hair using hydrochloric acid and methanol. Clean-up uses solid-phase extraction with a mixed-mode cation exchanger, and measurement is by liquid chromatography with electrospray tandem mass spectrometry. The method was validated per the Society of Toxicological and Forensic Chemistry guidelines. Reference hair samples were created by soaking hair in a dimethyl sulfoxide/methanol solution of the analytes to allow incorporation; these fortified samples served for method development and as quality controls.

Synthesis of a psilocin hapten and a protein-hapten conjugate

Journal of Pharmacy and Pharmacology September 1, 2002 Christian Albers, Matthias Lehr, Justus Beike et al. 7 citations

Derivatives of psilocin with functionalized alkyl spacers at the indole nitrogen were synthesized as haptens for a radioimmunoassay. The 3-aminopropyl and 4-aminobutyl analogues decomposed during synthesis, but the 3-carboxypropyl derivative was stable. This compound was coupled to bovine serum albumin (BSA) via N-hydroxysuccinimide ester-mediated conjugation. Mass spectrometry showed an average incorporation of 4–5 psilocin hapten molecules per BSA molecule, characterizing the protein–hapten conjugate.