ABSTRACT
Urine has become the most widely accepted specimen used for the detection of drug abuse. The popularity of this matrix for drug testing is probably due to the fact that, unlike blood, the collection of a urine sample does not require medical supervision. However, to ensure that the urine sample is authentic, it is often necessary to observe the subject producing the specimen. This invasion of privacy may cause embarrassment to some individuals and result in resistance to participation in a drug testing programme. Since most drugs of abuse are eliminated from the body within two to three days after use, urine analysis is also limited in its ability to detect drug exposure. If it is known that a drug screen will be required on a certain day, as a condition of employment for example, a few days’ abstinence prior to the urine being collected will result in the drug user going undetected. It is because of these problems associated with urine analysis that alternative specimens have been investigated for their potential as reliable indicators of drug exposure. To date, the most promising matrix for the detection of drug abuse appears to be hair.
