Drug Tests - Blood, Serum, Plasma

Blood, serum or plasma are the matrices of choice for toxicological analyses if the objective is to assess the acute impact of a drug of abuse on a person. This is typically the case in roadside testing and post-accident workplace drug testing or when there is objective evidence of impairment (e.g. aberrant driving) or in case of accident. The detection of drugs (cocaine, cannabis etc) in the blood strongly suggest impairment.

Blood samples should not be used for a control of abstinence, since alcohol and drugs are rapidly metabolized. After 24 h the drug concentrations are most often very low and substances can not be detected any more.

The levels of alcohol or drugs in the blood generally correlate with the intoxicative effects (deviant behaviour, adverse effects) and impairment. In contrast the concentrations in urine or hair do not allow any conclusions on the behaviour of a person at the time of sample collection.

Further information on relevant topics

MPA Fitness to Drive

In most industrial countries if a driver loses his driving license as a result of drug or alcohol offense he has to prove abstinence for several months up to one year. The exact conditions of drug testing in urine or hair are different from country to country and depend on the individual situation.

Dried Blood Samples

Chromatographic drug analyses (LC-MS/MS) in capillary blood and DBS (dried blood samples) respectively are of increasing importance.

Meconium

Drug abuse during pregnancy poses a serious threat to the normal development of the foetus.

Urine

For many years, urine has been the preferred specimen for drug of abuse testing. Depending on the substance or metabolite tested, the type of consumption (smoking, sniffing, injection), the dose and the frequency of consumption, drugs can be measured for several days or weeks. Samples then are collected under direct supervision to minimize manipulation attempts.

Hair

In the last few years hair testing for drugs has been rapidly gaining recognition. During hair growth (about 1 cm per month for head hair) drugs of abuse and their metabolites are continuously incorporated and deposited into the hair matrix following consumption of alcohol or drugs.

Saliva

The testing of drugs in saliva is a rather new alternative to the analysis of drugs in blood or urine. Particularly in workplace drug testing, a sample can be collected without medical intervention to prove or exclude exposure to drugs of abuse.