Natural durability transfer from sawmill residues of white cypress (Callitris glaucophylla). - Part 4: Analysis of extracts and treated wood for active components
IRG/WP 00-20215
Hui Jiang, M J Kennedy, L M Stephens
In order to facilitate the commercial implementation of a large project aimed at recovering 'waste' durability components from sawmill residues of Callitris glaucophylla, it has been essential to develop analytical methodology for the important bioactive components of the heartwood extract. This methodology will be used 1) to standardise the activity of successive production batches, ensuring that batch-to-batch variation is controlled, and 2) to monitor the penetration and retention of active components in extract-treated wood, ensuring that treatment quality is controlled. Analytical techniques used through the project have included both LC/MS and GC/MS, but as most of the extract activity against termites and fungi has now been demonstrated to reside in the lighter fractions, we have concentrated on GC/MS for the routine methodology for both extract activity and wood retention. Penetration is monitored by the application of a chromazurol S spot-test to a freshly cut transverse section. Both cypress heartwood and penetrated sapwood turn red-purple under the conditions of the test, which is not necessarily specific for cypress extractives, but nevertheless useful for routine monitoring of penetration of cypress extracts.