ABV
Alcohol by volume: the percentage of a beverage's volume that is ethanol.
Alcohol biomarker
A measurable substance or biological change used as evidence related to alcohol exposure or drinking pattern.
Analytical specificity
How well a laboratory method identifies the intended substance without interference from other compounds.
Blood alcohol concentration (BAC)
The amount of ethanol in blood. BAC addresses current or recent ethanol presence and is not equivalent to an EtG result.
Confirmation test
A more analytically specific test used to verify or quantify a screening result, commonly involving mass spectrometry.
Creatinine
A normal urine constituent used as an indicator of sample concentration and possible dilution.
Cutoff
The concentration at or above which a laboratory or device classifies a result as positive under its reporting rule.
Detection window
The period during which a biomarker may remain measurable above a test's cutoff after exposure.
Direct alcohol biomarker
A compound formed from ethanol or in ethanol's presence, such as EtG, EtS, or PEth.
Dilute specimen
A urine sample with low concentration indicators, often including low creatinine, under the applicable laboratory policy.
Ethanol
Ethyl alcohol: the psychoactive alcohol in beer, wine, spirits, and many alcohol-containing products.
EtG
Ethyl glucuronide, a direct ethanol metabolite commonly measured in urine and sometimes in hair.
EtS
Ethyl sulfate, a direct ethanol metabolite produced through sulfation and often used alongside EtG.
False negative
A negative classification even though the target exposure occurred, such as when concentration has fallen below the cutoff.
False positive
A positive classification that does not accurately represent the exposure being investigated; the phrase can refer to analytical interference or misinterpreted incidental exposure.
Glucuronidation
The metabolic process that joins glucuronic acid to another substance; this pathway forms ethyl glucuronide from ethanol.
Immunoassay
A test using antibody-based recognition to screen or measure a target such as EtG.
Incidental exposure
Contact with ethanol from a source other than beverage drinking, such as some sanitizers, mouthwashes, foods, or medicines.
LC-MS/MS
Liquid chromatography–tandem mass spectrometry, a highly specific analytical method used to separate, identify, and quantify compounds.
Limit of detection
The lowest concentration a method can reliably distinguish from the absence of the analyte under defined conditions.
Limit of quantification
The lowest concentration a method can quantify with acceptable analytical performance.
Metabolite
A substance created or changed by the body's metabolic processes.
ng/mL
Nanograms per millilitre, a common unit for quantitative urine EtG concentrations.
PEth
Phosphatidylethanol, a direct alcohol biomarker formed in blood-cell membranes in the presence of ethanol.
Positive result
A result at or above the stated cutoff. It supports detection of the analyte but does not automatically establish exact dose, time, or impairment.
Screening test
An efficient initial test designed to identify samples that may require confirmation or further interpretation.
Sensitivity
The proportion of relevant exposures that a test identifies under a defined study design, cutoff, and time frame.
Specificity
The proportion of comparison samples that a test correctly classifies as negative under defined conditions.
Standard drink
A country-specific unit representing a defined amount of pure ethanol; the definition is not globally uniform.
Urine normalization
Adjustment of a urine analyte relative to a concentration marker such as creatinine to reduce some dilution-related variation.
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