Technische Universität München

The Entrepreneurial University

Chemical and physical manipulation is the use of substances or methods in order to alter an urine sample. For example, using someone else’s urine for the sample or using epitestosterone or bromantane. Particularly, chemical and physical manipulation consists of the use of substances and/or methods which may tamper or attempting to tamper, in order to alter the integrity and validity of samples collected during doping controls. The chemical and physical manipulation of the samples is prohibited. It includes but is not limited to catheterization, urine substitution and/or alteration.

Furthermore, intravenous infusions are prohibited, except as a legitimate medical treatment. Injections associated with needle sharing may be associated with bruising, infections, fibrosis, neuro-vascular injury, risks of acquiring AIDS, hepatitis (B, C) and other blood-borne diseases. It is reported a 25% rate of needle sharing among adolescent doping substance users.

Chemical and physical manipulation is the last in frequency of use doping class by 0.1% of all adverse analytical findings worldwide. Physical than chemical manipulation is usually the preferred process.

There are a number of chemical and physical manipulation techniques such as the use of masking agents like probenecid, which blocks the renal excretion of testosterone, providing substitute urine samples for testing and chemical manipulation of urine to be tested. Probenecid is used to mask the use of doping substances (masking agent), anabolic drugs in particular, by delaying their elimination. The medical application of probenecid is to treat gout rheumatism. However the most frequently used masking agents are finasteride 15.2% and epitestosterone 5.2% of all masking agents occurrences.

Doping tests therefore screen for masking agents and analyze a range of chemical and physical properties of urine to detect manipulation of the sample.