Testing Terminology as Told by Lextox

The world of hair drug and alcohol testing can be complex, the amount of professional and scientific experience that both our laboratory and reporting scientist teams have brings with it a whole glossary of words, terms, acronyms and phrases.

In this post we are going to simplify and explain some of our most frequently used terminology to ensure that you have a clear understanding of our Analysis Results and Expert Reports.

Alcohol Biomarker

• A marker which can be found in hair when alcohol has been consumed. See ethyl glucuronide (EtG) and EtPa (ethyl palmitate) below for more information.

Chain of Custody (CoC)

• A documented record of the collection of the physical sample that identifies the sample belonging to the individual and includes additional information relevant to the requested testing.

Chronic excessive

• Currently, the Society of Hair Testing (see below) states that chronic excessive alcohol drinking corresponds to an average consumption of 60 grams of pure ethanol (alcohol) per day over several months. In the UK, 1 unit of alcohol is defined as 8 grams or 10 millilitres of alcohol, so 60 grams of alcohol equates to 7.5 units.

Cut-off

• This is the level used to determine if an analyte has been detected or not detected after the hair sample analysis. Each substance has its own cut-off level and this level may vary depending on the method of analysis used.

Ethyl glucuronide (EtG)

• EtG is a metabolite (see below) produced by the body after the consumption of alcohol (ethanol). EtG is soluble in water and as such is susceptible to be leached out of the hair through normal hygiene practices or through the use of cosmetic treatments (hair dyes).

Expert

• Our team of reporting scientists are otherwise known as our ‘Experts’. They are fully qualified and experienced in presenting expert evidence relating to our toxicological analysis results and reports in a courtroom setting, including Family, Crown and High Court.

Ethyl palmitate (EtPa)

• The alcohol marker EtPa is a by-product produced by the body after the consumption of alcohol. In contrast to EtG, EtPa is produced throughout the body whereas EtG is produced via the liver. It is also not soluble in water, however is still sensitive to hair treatments.

Gas chromatography-mass spectrometry (GC-MS or GC-MS/MS)

• One of the methods Lextox use to analyse hair samples is gas chromatography with tandem mass spectrometry (GC-MS/MS). This is a separation and identification technique used to identify and quantify substances. It is a highly sensitive and specific technique so, for example, when cocaine is detected it can only be cocaine and not any other substance.

Liquid chromatography with mass spectrometry (LC-MS or LC-MS/MS)

• Another method Lextox use to analyse hair samples is liquid chromatography with tandem mass spectrometry (LC-MS/MS). It is similar to GC-MS/MS in that it is a separation and identification technique used to identify and quantify substances. Similarly it is a highly sensitive and specific technique so, for example, when cocaine is detected it can only be cocaine and not any other substance.

Metabolite

• A substance that is formed by the body when a drug is used. Metabolites are a product of metabolism, the body’s way of eliminating drugs after use.

Segmentation/sectioning

• There are two types of available hair drug testing options, the first is an overview analysis and the second is a segmented/sectional month-by-month analysis. ‘ The latter involves segmenting (cutting) scalp hair samples into monthly 1cm sections to help show a trend (i.e. increase or decrease) of drugs detected.

Society of Hair Testing (SoHT)

• The Society of Hair Testing (SoHT), an international organisation joining all scientists dealing with hair analysis in a forensic context. Their guidelines are acknowledged as the current industry standard for family law.

Telogen

• Telogen is the resting phase of the hair cycle in which hair growth does not occur. The hair growth cycle comprises of three phases, actively growing (anagen phase), transition (catagen phase) and resting (telogen phase). There are significant differences in the relative proportions of actively growing hair and resting hair between different areas on the body.

UKAS

• UKAS (the United Kingdom Accreditation Service) is the only national accreditation body which has been recognised by the government to assess against internationally agreed standards, organisations that provide certification, testing, inspection and calibration services. This accreditation demonstrates the competency of our laboratory in testing to ensure reliability of the analysis results and delivers confidence in our service.

If you have any further queries on our most frequently used terminology please visit our FAQs page for more information or get in touch via [email protected] to ask one of our highly experienced team of Experts a question.