Alcohol is the most abused substance in the U.S., and it has been linked to several crimes and accidents. It is also a major concern among families because of children being exposed to the substance at such a young age from at least one parent who is dependent on alcohol.
In this article, we will discuss how alcohol can be detected in the system through what is known as Alcohol EtG testing, or EtG Alcohol Test.
What is EtG?
Ethyl Glucuronide (EtG) is a metabolite of ethanol, the primary substance found in beer, wine and liquor produced through the process of fermentation of starches, sugars and yeast. Ethanol is the specific substance that makes one become intoxicated.
Ethanol can be excreted from the body in several ways, namely:
- Direct excretion of ethanol (5-10%) in urine, breath and sweat.
- Metabolic excretion by conversion to acetaldehyde.
- Metabolic excretion by conversion of ethyl glucuronide and ethyl sulfate which are both eliminated through urination.
Most of these detectable excretory products in urine can be detected for short period of time.
The presence of EtG in urine is a clear indication of alcohol being ingested. In contrast to ethanol, EtG stays in the system for up to 80 hours,
What is an Alcohol EtG Test?
An alcohol EtG test or EtG urine alcohol test is used to determine, evaluate and monitor an individual who is perceived to have consumed alcohol. EtG testing uses an immunoassay screen with LC/MS/MS confirmation of any positive result from a previous screening. The confirmatory screening is done along with EtG alcohol testing.
The key benefits of using an EtG test are as follows:
- Convenient: EtG testing can be done on urine samples along with other drug testing panels.
- Accuracy: It is able to detect the most recent usage more accurately (up to 80 hours after consumption). EtG is only evident when alcohol is consumed.
- Modern: The tests are performed by LC/MS/MS on modern equipment. This is very ideal in cases when zero tolerance and abstinence to alcohol is a requirement.
- Warning: It acts as an early warning system to detect trends towards relapse.
- Longevity: It can determine alcohol ingestion in the last 3 to 4 days.
- Support for treatment: It allows monitoring in alcohol treatment programs.
Frequently Asked Questions
Here are some of the most frequently asked questions about alcohol EtG test, and the answer corresponding to each:
How long can EtG be detected in urine?
The actual alcohol in the body can be detected by using traditional laboratory methods that reflect current use within the past few hours, depending on the amount of alcohol consumed. The presence of EtG in urine can be determined up to 3-4 days after ingestion or approximately 80 hours after ethanol has been eliminated from the body.
EtG urine test is more accurate in determining the recent injection of alcohol than measuring the presence of ethanol itself.
Why choose EtG alcohol test over saliva and breath tests?
EtG Alcohol Urine test can provide you with an immediate result with accuracy comparable to a test performed in a laboratory. The saliva and breath tests may also detect the presence of alcohol; however, the EtG test allows detection of alcohol up to after 80 hours after the last ingestion.
How accurate and reliable is EtG test?
EtG is a direct metabolite of ethanol and its detection in urine is very highly specific. Because EtG occurs only in the presence of ethanol, detecting the compound is synonymous to saying that there is ethanol in the system.
Can the exact amount of alcohol be determined through EtG test?
Higher amount of EtG may indicate a large amount of alcohol consumption but could not exactly measure or determine the amount of alcohol intake as well as how recent the alcohol was consumed. The presence of EtG in urine can only be a determinant of alcohol in urine within the past 80 hours prior to testing.
Can residual EtG be detected in the urine of long-term alcoholics who abstain?
The limitation of EtG test is that it cannot detect presence of ethanol in people who have consumed it more than 80 hours prior to the test.
Will urine alcohol produced by fermentation affect EtG results?
Ethanol in vitro is the produced in the bladder or specimen container due to fermentation of urine samples containing sugar in diabetes, bacteria or yeast. Since the ethanol produced is not metabolized in the liver, EtG will not be produced and will not be detected in the urine containing alcohol as a result of fermentation. Only EtG that comes directly from consumed alcohol is detected by the EtG test.
How stable is EtG in urine at room temperature?
It is believed that EtG in urine for more than 4 days is stable at room temperature. Recent studies indicate that heating the urine sample at 100 degrees Celsius can increase the stability of EtG. This clearly shows that heat does not cause any breakdown of EtG. There is no artificial formation of EtG found to occur following a prolonged storage of urine sample at room temperature.
Will using “incidental alcohol” trigger a positive result?
Incidental exposure to alcohol such as mouthwash and over-the-counter drugs may produce EtG concentrations in excess of 100ng/l. However, if the ethanol detected in urine indicates >250 ng/ml, then it is a clear evidence of alcohol ingestion.
For cases where there has been a positive result from a previous test on the presence of alcohol, the EtG test confirms if the alcohol level is indeed coming from alcohol ingestion and is not a result of alcohol fermentation in the body.
What are the methods used to detect EtG?
Here are the scientific methods used in detecting EtG:
- Immunoassay (EIA or ELISA): This has a limited specificity and sensitivity with a limit of detection of approximately 1000 ng/ml.
- Gas Chromatography/Mass Spectrometry (GC/MS)
- Liquid Chromatography/Mass Spectrometry (LC/MS)
- Liquid Chromatography/Mass Spectrometry/Mass Spectrometry (LC/MS/MS): This method utilizes the most technologically advanced instrumentation that is currently available in forensic and clinical toxicology and provides the highest sensitivity of all methods. The limit of detection is 250 ng/ml.
How is EtG Alcohol Urine Test done?
A sample of urine is taken from the individual wherein the dipstick is immersed into the urine specimen. Compare the color obtained from the dipstick from the provided alcohol color chart for results.
A positive indication of alcohol in the urine specimen occurs when it exceeds 300ng/ml.
Can EtG result be accepted as valid evidence in courts of law?
An EtG result may be presented as evidence in hearings and court proceedings. It has become a very helpful tool in persecuting offenders who were charged with DUI and alcohol-related injuries and fatalities.
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