Effects of External Decontamination of Methamphetamine in Juvenile Hair

Methamphetamine is a common illicit substance abused in the United States. Hair is one matrix that is analyzed to determine the presence and concentration of methamphetamine. When hair is analyzed, an external decontamination step is commonly performed prior to drug extraction to avoid a potential positive result from environmental exposure in someone that has not ingested the drug themselves. In child-custody scenarios, however, it is important to know if a child is often around such illicit substances. This study serves to assess if there is a significant difference in methamphetamine concentrations in samples from children up to 12 years old depending on if this external decontamination procedure has been performed. This was done by obtaining a series of samples that had been previously determined to be positive for methamphetamine and samples that had tested positive through initial drug screening but negative upon confirmatory testing. Aliquots were taken and divided into two portions, one including the decontamination step and one to skip it, before extraction. Each sample was then run using liquid chromatography-tandem mass spectrometry (LC/MSMS) and washed and unwashed sample concentrations were compared. It was determined that significant differences were common between samples that were externally decontaminated prior to drug extraction and those that were not. As a result of this study, it is suggested that hair samples obtained from children in child-custody investigations should not include an external decontamination step as this reduces hair drug concentrations in hair, which may cause children to remain in hazardous environments