Testing begins with a screening assay. If the screen is positive, then the liquid chromaography-tandem mass spectrometry confirmation with quantification will be performed at an additional charge.
Screening for drug abuse involving alcohol.
1. Collect a random urine specimen.
2. Submit 20 mL in 1 container.
3. No preservative.
Care should be taken when interpreting results since there are many factors (eg, fluid intake and other biologic factors) that may influence a urine test result. It is possible that substances other than those investigated in the specificity study may interfere with the test and cause false-positive or negative results.
LC-MS/MS Confirmation (as needed)
This procedure uses immunoassay reagents that are designed to produce a negative result when no drugs are present in a natural (ie, unadulterated) specimen of urine; the assay is designed to have a high true-negative rate. Like all immunoassays, it can have a false-positive rate due to cross-reactivity with natural chemicals and drugs other than those they were designed to detect. The immunoassay also has a false-negative rate to the antibodyâ€™s ability to cross-react with different drugs in the class being screened for.
Ethyl glucuronide is a direct metabolite of ethanol that is formed by enzymatic conjugation of ethanol with glucuronic acid. Alcohol in urine is normally detected for only a few hours, whereas ethyl glucuronide can be detected in the urine for 1 to 3 days.
Screening cutoff concentration:
Ethyl Glucuronide: 500 ng/mL
This assay only provides a preliminary analytical test result. A more specific alternative method (ie, liquid chromatography-tandem mass spectrometry; LC-MS/MS) must be used to obtain a confirmed analytical result. A positive result using the ethyl glucuronide screen indicates only the potential presence of ethyl glucuronide and does not necessarily correlate with the extent of physiological and psychological effects.