ENZYMATIC ASSAY OF HYDROXYBUTYRIC ACID MONOMER FORMATION IN POLY(BETA-HYDROXYBUTYRATE) DEGRADATION STUDIES

A novel method for monitoring the degradation of poly(beta-hydroxybuty rate) based on the enzymatic assay of beta-hydroxybutyrate (HBA) monom ers has been developed. The method is particularly applicable to forms of the polymer, such as fibre and microcapsules, for which convention al surface and gravimetric monitoring techniques are not readily appli cable. The method involves the use of enzyme HBA dehydrogenase in a re action that converts nicotinamide adenine dinucleotide (NAD) to its re duced form (NADH). The conversion is associated with an increase in li ght absorbtion at 340 nm which thus serves to indicate the concentrati on of HBA monomer in the sample. The application of the methodology to the degradation of poly(beta-hydroxybutyrate) gel spun fibres has bee n used to demonstrate its potential use as a quantitative monitoring t echnique in the study of the hydrolysis of this polymer.