Evidence based decontamination protocols for the removal of external Δ9-tetrahydrocannabinol (THC) from contaminated hair

W.F. Duvivier, R.J.P. Peeters, T.A. van Beek, M.W.F. Nielen

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5 Citations (Scopus)

Abstract

External contamination can cause false positive results in forensic hair testing for drugs of abuse and is therefore a major concern when hair evidence is used in court. Current literature about decontamination strategies is mainly focused on external cocaine contamination and no consensus on the best decontamination procedure for hair samples containing cannabinoids has been reached so far. In this study, different protocols with solvents, both organic as well as aqueous, were tested on blank and drug user hair for their performance on removing external cannabis contamination originating from either smoke or indirect contact with cannabis plant material. Smoke contamination was mimicked by exposing hair samples to smoke from a cannabis cigarette and indirect contact contamination by handling hair with cannabis contaminated gloves or hands. Δ9-tetrahydrocannabinol (THC) levels in the hair samples and wash solvents were determined using liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis. Aqueous surfactant solutions removed more THC contamination compared to water, but much less than organic solvents. Methanol, dichloromethane and chloroform were most efficient in removing THC contamination. Due to its lower environmental impact, methanol was chosen as the preferred decontamination solvent. After testing of different sequential wash steps on externally contaminated blank hair, three protocols performed equally well, removing all normal level and more than 99% of unrealistically high levels of external cannabis contamination. Thorough testing on cannabis users’ hair, both as such and after deliberate contamination, showed that using these protocols all contamination could be washed from the hair while no incorporated THC was removed from truly positive samples. The present study provides detailed scientific evidence in support of the recommendations of the Society of Hair Testing: a protocol using a single methanol wash followed by a single aqueous SDS solution wash, followed by a Milli-Q water rinsing step, is suggested as the preferred decontamination protocol to remove external cannabis contamination from hair while preserving the incorporated compounds.
Original languageEnglish
Pages (from-to)110-118
JournalForensic Science International
Volume259
DOIs
Publication statusPublished - 2016

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Dronabinol
Decontamination
Hair
Cannabis
Smoke
Methanol
Cannabinoids
Water
Methylene Chloride
Street Drugs
Chloroform
Tandem Mass Spectrometry
Drug Users
Cocaine
Surface-Active Agents
Tobacco Products
Liquid Chromatography
Hand

Cite this

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title = "Evidence based decontamination protocols for the removal of external Δ9-tetrahydrocannabinol (THC) from contaminated hair",
abstract = "External contamination can cause false positive results in forensic hair testing for drugs of abuse and is therefore a major concern when hair evidence is used in court. Current literature about decontamination strategies is mainly focused on external cocaine contamination and no consensus on the best decontamination procedure for hair samples containing cannabinoids has been reached so far. In this study, different protocols with solvents, both organic as well as aqueous, were tested on blank and drug user hair for their performance on removing external cannabis contamination originating from either smoke or indirect contact with cannabis plant material. Smoke contamination was mimicked by exposing hair samples to smoke from a cannabis cigarette and indirect contact contamination by handling hair with cannabis contaminated gloves or hands. Δ9-tetrahydrocannabinol (THC) levels in the hair samples and wash solvents were determined using liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis. Aqueous surfactant solutions removed more THC contamination compared to water, but much less than organic solvents. Methanol, dichloromethane and chloroform were most efficient in removing THC contamination. Due to its lower environmental impact, methanol was chosen as the preferred decontamination solvent. After testing of different sequential wash steps on externally contaminated blank hair, three protocols performed equally well, removing all normal level and more than 99{\%} of unrealistically high levels of external cannabis contamination. Thorough testing on cannabis users’ hair, both as such and after deliberate contamination, showed that using these protocols all contamination could be washed from the hair while no incorporated THC was removed from truly positive samples. The present study provides detailed scientific evidence in support of the recommendations of the Society of Hair Testing: a protocol using a single methanol wash followed by a single aqueous SDS solution wash, followed by a Milli-Q water rinsing step, is suggested as the preferred decontamination protocol to remove external cannabis contamination from hair while preserving the incorporated compounds.",
author = "W.F. Duvivier and R.J.P. Peeters and {van Beek}, T.A. and M.W.F. Nielen",
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Evidence based decontamination protocols for the removal of external Δ9-tetrahydrocannabinol (THC) from contaminated hair. / Duvivier, W.F.; Peeters, R.J.P.; van Beek, T.A.; Nielen, M.W.F.

In: Forensic Science International, Vol. 259, 2016, p. 110-118.

Research output: Contribution to journalArticleAcademicpeer-review

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AU - Duvivier, W.F.

AU - Peeters, R.J.P.

AU - van Beek, T.A.

AU - Nielen, M.W.F.

PY - 2016

Y1 - 2016

N2 - External contamination can cause false positive results in forensic hair testing for drugs of abuse and is therefore a major concern when hair evidence is used in court. Current literature about decontamination strategies is mainly focused on external cocaine contamination and no consensus on the best decontamination procedure for hair samples containing cannabinoids has been reached so far. In this study, different protocols with solvents, both organic as well as aqueous, were tested on blank and drug user hair for their performance on removing external cannabis contamination originating from either smoke or indirect contact with cannabis plant material. Smoke contamination was mimicked by exposing hair samples to smoke from a cannabis cigarette and indirect contact contamination by handling hair with cannabis contaminated gloves or hands. Δ9-tetrahydrocannabinol (THC) levels in the hair samples and wash solvents were determined using liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis. Aqueous surfactant solutions removed more THC contamination compared to water, but much less than organic solvents. Methanol, dichloromethane and chloroform were most efficient in removing THC contamination. Due to its lower environmental impact, methanol was chosen as the preferred decontamination solvent. After testing of different sequential wash steps on externally contaminated blank hair, three protocols performed equally well, removing all normal level and more than 99% of unrealistically high levels of external cannabis contamination. Thorough testing on cannabis users’ hair, both as such and after deliberate contamination, showed that using these protocols all contamination could be washed from the hair while no incorporated THC was removed from truly positive samples. The present study provides detailed scientific evidence in support of the recommendations of the Society of Hair Testing: a protocol using a single methanol wash followed by a single aqueous SDS solution wash, followed by a Milli-Q water rinsing step, is suggested as the preferred decontamination protocol to remove external cannabis contamination from hair while preserving the incorporated compounds.

AB - External contamination can cause false positive results in forensic hair testing for drugs of abuse and is therefore a major concern when hair evidence is used in court. Current literature about decontamination strategies is mainly focused on external cocaine contamination and no consensus on the best decontamination procedure for hair samples containing cannabinoids has been reached so far. In this study, different protocols with solvents, both organic as well as aqueous, were tested on blank and drug user hair for their performance on removing external cannabis contamination originating from either smoke or indirect contact with cannabis plant material. Smoke contamination was mimicked by exposing hair samples to smoke from a cannabis cigarette and indirect contact contamination by handling hair with cannabis contaminated gloves or hands. Δ9-tetrahydrocannabinol (THC) levels in the hair samples and wash solvents were determined using liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis. Aqueous surfactant solutions removed more THC contamination compared to water, but much less than organic solvents. Methanol, dichloromethane and chloroform were most efficient in removing THC contamination. Due to its lower environmental impact, methanol was chosen as the preferred decontamination solvent. After testing of different sequential wash steps on externally contaminated blank hair, three protocols performed equally well, removing all normal level and more than 99% of unrealistically high levels of external cannabis contamination. Thorough testing on cannabis users’ hair, both as such and after deliberate contamination, showed that using these protocols all contamination could be washed from the hair while no incorporated THC was removed from truly positive samples. The present study provides detailed scientific evidence in support of the recommendations of the Society of Hair Testing: a protocol using a single methanol wash followed by a single aqueous SDS solution wash, followed by a Milli-Q water rinsing step, is suggested as the preferred decontamination protocol to remove external cannabis contamination from hair while preserving the incorporated compounds.

U2 - 10.1016/j.forsciint.2015.12.014

DO - 10.1016/j.forsciint.2015.12.014

M3 - Article

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JO - Forensic Science International

JF - Forensic Science International

SN - 0379-0738

ER -