Carboxy-THC in Washed Hair: Still the Reliable Indicator of Marijuana Ingestion

Hill, Virginia; Schäffer, Michael; Stowe, G. Neil

doi:10.1093/jat/bkw031

Cited by 18 publications

(20 citation statements)

References 8 publications

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“…15 A series of experiments including heavy smoke exposure; cross contamination in the presence of moisture from THC-COOH-positive hair or fabric, respectively; or soaking of hair in THC-COOH solutions of 10 pg/mL showed that an adequate washing procedure is able to completely remove potential external contamination. 16 Reportedly, the LLOQ of the analytical method applied was 0.1 pg THC-COOH/mg hair being 2 times lower than the LLOQ recom- Although analysis of a higher number of hair samples will be desirable, this study extends the previously published literature. A higher number of samples has been evaluated for cannabis use than previously reported.…”

Section: Comparison Of the Results For Thc Thc-cooh Und Thc-oh Frmentioning

confidence: 62%

“…Although having been questioned, detection of THC‐COOH is generally accepted as proof of cannabis use . A series of experiments including heavy smoke exposure; cross contamination in the presence of moisture from THC‐COOH‐positive hair or fabric, respectively; or soaking of hair in THC‐COOH solutions of 10 pg/mL showed that an adequate washing procedure is able to completely remove potential external contamination …”

Section: Resultsmentioning

confidence: 99%

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Proof of active cannabis use comparing 11‐hydroxy‐∆9‐tetrahydrocannabinol with 11‐nor‐9‐carboxy‐tetrahydrocannabinol concentrations

Franz¹,

Skopp²,

Schwarz³

et al. 2018

Drug Testing and Analysis

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Testing hair for cannabis use has increasingly been scrutinised due to exposure to second-hand smoke or environmental contamination. Confirmation of drug use involving detection of metabolites such as 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH) and 11-hydroxy-delta-9-tetrahydrocannabinol (THC-OH) having very rarely been considered. We developed a new, simplified procedure with regard to expenditure of time and material to determine delta-9-tetrahydrocannabinol (THC, qualitatively), as well as THC-OH and THC-COOH (quantitatively) from 587 hair samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS) which was compared to hitherto established methods (n = 3). Compared to conventional methanolic extraction alkaline dissolution resulted in higher concentrations for THC-OH. Concentrations determined from specimens ranged from 0.01 to 18.7 ng THC/mg hair, 0.05-37.6 pg THC-OH/mg hair, and from 0.1 to 54.3 pg THC-COOH/mg hair. THC was detectable in 70.4% samples along with both metabolites from more than half of these samples. In 12.9% of THC-positive cases, neither THC-OH nor THC-COOH were present. In 8.9% of THC-negative cases, it was possible to detect metabolites either alone or in combination. THC-OH could more frequently be detected than THC-COOH and appeared to be less susceptible to cosmetic treatment. In summary, THC-OH turned out to be a further suitable marker to prove cannabis use. Determination of both metabolites is recommended to unequivocally differentiate consumption from external exposure or contamination.

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Section: Comparison Of the Results For Thc Thc-cooh Und Thc-oh Frmentioning

confidence: 62%

Section: Resultsmentioning

confidence: 99%

Proof of active cannabis use comparing 11‐hydroxy‐∆9‐tetrahydrocannabinol with 11‐nor‐9‐carboxy‐tetrahydrocannabinol concentrations

Franz¹,

Skopp²,

Schwarz³

et al. 2018

Drug Testing and Analysis

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show abstract

“…It has even been suggested that a major part of THC detectable in a drug smoker's hair actually originates from external contamination . The presumption of Moosmann et al that THC‐COOH could also be present in hair samples of non‐consuming individuals due to contamination by cannabis consumers via sebum/sweat has been challenged in a review by Berthet et al and the investigation of Hill et al…”

Section: Resultsmentioning

confidence: 99%

Can a threshold for 11‐nor‐9‐carboxy‐Δ⁹ ‐tetrahydrocannabinol in hair be derived when its respective concentration in blood serum indicates regular use?

Zinka

Epple

Schick

et al. 2018

Drug Testing and Analysis

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A 100 μg/L or higher concentration of 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) in blood serum is generally assumed to be associated with regular and/or heavy use of cannabis. At present, determination of the extent of cannabis use by means of the concentration of THC-COOH in hair has not been assessed. Therefore, we aimed at establishing a threshold for THC-COOH concentrations in hair to prove frequent consumption by comparing THC-COOH concentrations in 129 corresponding serum and hair samples, respectively. The concentration of THC-COOH in the serum was analyzed by gas chromatography-mass spectrometry and in the hair by liquid chromatography-tandem mass spectrometry. Data were statistically evaluated using receiver operating characteristic curves and contingency tables. Our results suggest that a THC-COOH concentration of ≥4.2 pg/mg in hair was always accompanied by a THC-COOH concentration of at least 100 μg/L in blood serum. Should this be confirmed by further studies of a larger study population, a hair concentration of 4.2 pg/mg THC-COOH can be set as a threshold to predict regular and/or heavy consumption of cannabis even if no corresponding blood sample is available for analysis.

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“…This phenomenon was also described by other scientific research groups [7,8], and can be explained by the assays' limited sensitivity to detection of cannabis in hair samples. On the opposite side, other scientific researcher's states a scientific evidence of detection of cannabis abuse by means of hair analysis should involve the sensitive detection of the THC metabolite THC carboxylic acid (THC-COOH) in a very lower detection limit, (pg) detection unit [9][10][11].…”

Section: Resultsmentioning

confidence: 99%

Validity of Substances of Abuse Detection in Hair by Biochips Array Technology

Ragab¹,

Al-Mazroua²,

El-Harouny³

et al. 2018

J Alcohol Drug Depend

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Using hair as a biological specimen to analyze drug abuse has been receiving elevated attention during last years because of flexibility of collection procedure and because hair does not autolysis like other body fluids or tissues. Hair testing provides a broad-spectrum detection window after drug exposure than urine testing. Hair analysis has specific criteria that it provides a way of obtaining information that cannot be acquired by other commonly used forensic toxicology analytical procedures, such as blood or urine analysis. In the hair matrix, many xenobiotics are trapped permanently, in disparity to the situation with blood or urine where they are only identifiable for a few hours or days. Subsequently substance of abuse detection by hair analysis should be the target procedure in the clinical and forensic toxicology aspect when the evaluation of repeated or chronic exposure to a drug is indicated, e.g. in the case of pre-employment/workplace testing, criminal affairs or a driving license restoration. In the current study, seventy cases of the application of hair analyses using this technique for the determination of substances of abuse (opiates, cannabis, amphetamine, barbiturate, benzodiazepines, and cocaine) are investigated. Analytical toxicology procedure for detection of substance of abuse is critical important: Biochips array technology that confirmed with GC/MS has proved to be a highly sensitive and specific technique for the detection of substances of abuse at very low concentrations in hair except for cannabis.

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Carboxy-THC in Washed Hair: Still the Reliable Indicator of Marijuana Ingestion

Cited by 18 publications

References 8 publications

Proof of active cannabis use comparing 11‐hydroxy‐∆9‐tetrahydrocannabinol with 11‐nor‐9‐carboxy‐tetrahydrocannabinol concentrations

Proof of active cannabis use comparing 11‐hydroxy‐∆9‐tetrahydrocannabinol with 11‐nor‐9‐carboxy‐tetrahydrocannabinol concentrations

Can a threshold for 11‐nor‐9‐carboxy‐Δ⁹ ‐tetrahydrocannabinol in hair be derived when its respective concentration in blood serum indicates regular use?

Validity of Substances of Abuse Detection in Hair by Biochips Array Technology

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Carboxy-THC in Washed Hair: Still the Reliable Indicator of Marijuana Ingestion

Cited by 18 publications

References 8 publications

Proof of active cannabis use comparing 11‐hydroxy‐∆9‐tetrahydrocannabinol with 11‐nor‐9‐carboxy‐tetrahydrocannabinol concentrations

Proof of active cannabis use comparing 11‐hydroxy‐∆9‐tetrahydrocannabinol with 11‐nor‐9‐carboxy‐tetrahydrocannabinol concentrations

Can a threshold for 11‐nor‐9‐carboxy‐Δ9 ‐tetrahydrocannabinol in hair be derived when its respective concentration in blood serum indicates regular use?

Validity of Substances of Abuse Detection in Hair by Biochips Array Technology

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Can a threshold for 11‐nor‐9‐carboxy‐Δ⁹ ‐tetrahydrocannabinol in hair be derived when its respective concentration in blood serum indicates regular use?