[Use of ethanol naturally enriched in carbon 13 for metabolic studies]

The ratio of carbon 13 to carbon 12 is higher in organic substances which originate from corn or cane, as compared to most higher plants. Cane alcohol or corn alcohol are enriched in carbon 13 as compared to common European foods. This discovery provided a new technique for alcohol metabolism studies with animals or men. The ratio of carbon 13 to carbon 12 is measured by mass spectrometry in the carbon dioxide expired after administration of cane or corn alcohol. This ratio increases significantly and reaches a maximum when the blood alcohol level has decreased considerably.