IMPROVED METHODOLOGY FOR STUDYING DIFFUSION, SORPTION AND DESORPTION IN TIMBER FUMIGATION

Methods to study movement of fumigant through timber were improved, an d procedures were developed that obviated the need for sampling lines. Movement for two fumigants (methyl bromide and carbonyl sulphide) thr ough, and sorption on, heartwood of softwood and hardwood were studied . Each fumigant,vas sorbed less on softwood than on hardwood and penet rated softwood better than hardwood. Neither fumigant penetrated acros s the grain. Carbonyl sulphide penetrated timber better than did methy l bromide, and was less sorbed on timber. A rapid method of solvent ex traction was developed to enable rapid estimation of the amount of int act fumigant sorbed in wood. This procedure enabled excellent recovery of methyl bromide as either intact fumigant or as bromide ion. (C) 19 97 Elsevier Science Ltd.