Resorption is the inclusion of a substance in the body. By consumption of alcohol (ethanol) a small proportion (just below 2 percent) is already absorbed in the mouth. Yet another part to a maximum of 20 percent will be absorbed in the stomach. The principal amount is absorbed in the colon and small intestine tract.
About the lungs cycle the alcohol reaches the pulmonary arterial circulation with oxygen-enriched blood (of which approximately 25% goes into the brain). The diffusion of alcohol takes place in the entire aqueous distribution volume of the body, but not in bone and fat tissue. The available mass distribution may be computed from the body mass by multiplication with the reduction factor after Widmark (0.7 for men, 0.6 for women) or more precisely by taking account of body size, body mass, age and sex according to Watson, most recently also by direct measurement. The difference between women and men is due to the lower aqueous distribution volume of women due to a higher proportion of fatty tissues.
The resorption is at least finished 2 hours after the end of drinking. Drinking of small amounts may be resorbed after 30-90 minutes (see the upward curve of the schematic representation). Higher alcohols (propanol, butanol and pentanol isomerers) are absorbed very quickly (approx. 30 minutes), the resorption of methanol may take up to 3 hours.
The resorption time is dependant by the filling of the stomach, and also the type of food (fat) is important.
Alcoholic solutions in higher concentrations may also be absoprbed on the skin. Therfore, a skin disinfection with alcohol before blood withdrawal for alcohol determination purpose is not permitted, although the resulting measurement error is virtually non-detectable.