The hair matrix offers a number of findings that are not given by other matrices, e.g., oral fluid, urine and blood, which can be used to demonstrate only recent drug use; recent being defined as a number of hours or days prior to sample collection. The wide range of detection available through the hair matrix, the ease of sample collection and storage, the stability of the analytes at ambient temperature and the presence of multiple metabolites for some drugs provide and clarify interpretation of results over extended time periods.

Today there are two primary roles (or applications) for drugs in hair analysis:

• Screening procedures that distinguish, on a presumptive basis, between negative (non-users) and positive (users) populations, including individuals who may have been indirectly exposed to drugs.

• Forensic procedures which unequivocally identify and quantify (where necessary) the drug (or drugs) which have been consumed, knowingly or otherwise by an individual.

Analysis

The first stage of hair analysis typically involves a range of screening tests to determine whether a drug (or drugs) might be present. Immunoassay is routinely chosen as the preferential screening test since the technique provides rapid, sensitive and relatively inexpensive means of determining whether many common drugs of abuse or similar compounds may be present in the hair. It is required that presumptive, positive immunoassay tests are followed by more specific analysis for the target analyte. Confirmatory and quantitative analysis is usually undertaken using gas chromatography (GC) or liquid chromatography (LC) coupled to a mass spectrometry detector – GC or LC/MS. Drug concentrations in hair are considerably lower than those found in other matrices, e.g., blood, urine and, as such, tandem mass spectrometry (MS/MS) is often used for confirmation purposes. Multisectional (or segmental) analysis involves taking a length of hair and cutting it into sections to measure drug use during shorter periods of time. Depending on the type of case, different strategies for segmentation may apply. Segmental hair analysis can be used to verify previous drug use/history and also periods of abstinence. The accuracy of segmental analysis depends on both the sampling and the segmentation procedure.

Hair analysis to investigate excessive alcohol intake

According to the World Health Organization and a literature survey, chronic excessive alcohol drinking corresponds to an average consumption of 60 grams of pure ethanol per day over several months. Ethylglucuronide (EtG) is a stable, non volatile and water-soluble direct metabolite of ethanol. EtG is formed as a result of the conjugation of ethanol with glucuronic acid during phase II metabolism. Gas (or liquid) chromatography coupled to tandem mass spectrometry can be used to detect and quantify EtG in a hair sample; it is a direct alcohol consumption marker. The consensus of the Society of Hair Testing (2012) is that a concentration equal to or greater than 30 picograms per milligram (30 pg/mg) of EtG in the 0-3 cm up to 0-6 cm proximal scalp hair segment strongly suggests repeated alcohol consumption; a concentration below 7 pg/mg indicates abstinence.

 Hair Testing with CNCFTS

CNCFTS Ltd provides accredited, analytical services and interpretation for the following drugs in hair analysis:

• Amphetamines

• Methlyamphetamines including Ecstasy

• Benzodiazepines and analogues including zolpidem and zopiclone

• Cannabinoids – THC, Hydroxy-THC and Carboxy-THC

• Cocaine and associated metabolites

• Opiates including 6-acetylmorphine

• Anabolic steroids

CNCFTS Ltd can also undertake analysis for ethylglucuronide (EtG).  EtG is a direct alcohol consumption marker that is formed during metabolism.

 If you wish to submit a hair sample for analysis, or if you have any questions concerning drugs in hair, please contact CNCFTS Ltd.