[Stability of esters in the blood in vitro]

The aim of this paper was to evaluate the lambda values of this group of solvents experimentally, by means of an analytical method which has already been used for other solvents. During our experiments we found that most acetates we tested (n-butyl-acetate; sec.butyl-acetate; ter-butyl-acetate; ethyl-acetate; amyl-acetate; methyl-acetate; n-propyl-acetate) were particularly unstable and hydrolyzed rapidly in alcohol and in the corresponding acid. The "in vitro" behaviour of these substances allow to draw the following conclusions: 1) For the acetates it is not possible to measure the values since the involved substances are chemically unstable in blood. 2) As it was shown by the half-life times of the "in vitro" acetates, the alcohols and the corresponding acids, are released rapidly in blood. 3) The biological monitoring of the acetates in expired air is not very significant; perhaps it is better to measure the corresponding alcohol in expired air. 4) In some cases the TLV of the alcohols is much lower than for the corresponding acetates; this finding and the rapid biotransformation we observed make us think that the TLV's proposed for some acetates are too high.