Analysis of ethanol and acetaldehyde recovery from perchloric acid-treated blood.

Recovery of acetaldehyde (0-20 microM) or ethanol (0-50 mM) added to blood and subsequently treated with perchloric acid (PCA) was evaluated using head-space gas chromatography and compared with controls. Using blood from five dogs, < 100% of acetaldehyde and ethanol was recovered from PCA-treated samples. Mathematical models of putative binding mechanisms indicated acetaldehyde partitioned simply between supernatant and PCA-induced precipitate and occupied < 1% of acetaldehyde binding sites on precipitate; ethanol partitioned simply between supernatant and precipitate and occupied > 62% of ethanol binding sites. The mathematical model also indicated acetaldehyde binding is 2500-fold stronger than ethanol binding. These results indicate as much as 46.4% of acetaldehyde may be bound to PCA-induced precipitate formed in whole blood. This loss of acetaldehyde is 3- to 4-fold greater than acetaldehyde loss caused by evaporation from PCA-treated blood.