Hair tests can detect long-term drug use, but external contamination risks false positives. Advanced analytical equipment now allows precise quantification of drugs in hair at picogram per milligram levels. In a family law case, DMT was found in the hair of a partner of a repetitive DMT smoker at 4 to 13 pg/mg across six 1-cm segments, with concentrations increasing from proximal to distal ends. This pattern and low concentrations indicate environmental contamination rather than ingestion, as older hair had longer contact with the drug. Even after decontamination, environmental drugs can remain bound to hair, enabling documentation of exposure.
A method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to detect psilocin, the active metabolite of psilocybin from magic mushrooms, in human hair. The technique involves incubating 10 mg of hair in acid methanol with a labeled internal standard, followed by chromatographic separation. The method was linear from 1 to 200 pg/mg, with a detection limit of 0.4 pg/mg and good precision. Analysis of hair from a regular magic mushroom user found psilocin levels of 2.5, 4.4, and 5.4 pg/mg in successive 1-cm segments. Cold conditions and protection from light are essential to prevent psilocin degradation during preparation.