1. A drug-test result may be questioned both as to whether it truly proves drug use and whether it proves resulting impairment.
2. Generally, an illegal drug can be found only in biological specimens collected while the subject feels the drug's active effect.
3. A change in saliva pH may increase the amount of cocaine found.
4. Marijuana metabolites or by-products disappear from urine in 24 to 72 hours.
5. All recreational drugs cause a loss in driving performance.
6. Sweat-test are reported as an equivalent of concentration in the blood.
7. A drug-recognition expert observes and documents five general areas of potential drug-use symptoms.
8. A subject taking therapeutic doses of hydrocodone may test positive for illegal opiates in a screening test.
9. An individual who does not use illegal drugs may, nevertheless, have drug residue in his or her hair.
10. Observing an effect that is consistent with use of a specific drug does not necessarily mean the effects seen are caused by the drug.
11. Generally speaking, presumptive tests will determine the presence of a specific drug.
12. A GC/MS analysis tests a drug for both its retention time and its ionic "fingerprint."
13. The best determination of drug influence via the Drug Evaluation and Classification method requires performing and completing the twelve steps in a standardized manner and determining if there is an alternative explanation for the effects seen.
14. Ethnicity may play a part in how much of a drug is incorporated into the subject's hair.
15. Selected ion monitoring is generally used to determine the quantity of a drug in a specimen, not just the presence of the drug.
16. Drug levels in saliva sample can often be reliably compared to blood levels.
17. An enzyme immunoassay (EIA) or radioimmunoassay (RIA) is a drug-use confirmation test.
18. A single 2-inch hair specimen may be able to show drug use or exposure over a several-month period.
19. A urine specimen result will be able to tell you what the corresponding blood level will be.
20. All presumptive drug tests must be confirmed via gas chromatograph (GC) or gas chromatograph/mass spectrometer (GC/MS) or a similar instrument.