Improved methods for the measurement of acetaldehyde concentrations in plasma and red blood cells

Research on the toxic effects of acetaldehyde (Ach) is hampered by analytical difficulties which have been overcome by two new methods suitable for the measurement of Ach in plasma and red blood cells. The first procedure involves rapid separation of plasma, deproteinization, and Ach derivatization with 2,4-dinitrophenylhydrazine (DNP). After extraction with isooctane, the Ach-DNP complex is separated by reverse-phase high performance liquid chromatography. Red blood cell Ach is measured by a modification of the semicarbazide method. The red blood cell hemolysate is mixed with the semicarbazide solution and the extract is injected into the head-space gas chromatograph. The procedure minimizes the artifactual Ach formation which interferes with the direct hemolysis method when human blood is used. After 0.3 g/kg of ethanol, Ach values of 1.5 +/- 0.2 and 9.9 +/- 2.3 microM were detected in plasma and red blood cells of healthy volunteers. These data indicate that an important fraction of Ach circulates in the red blood cells and can be missed or underestimated when only plasma Ach is measured.