Patent ID: 7785896

Claim:
A method for qualifying the distribution of an organic biocide within a composite wood product, the method comprising the steps of: providing the plurality of wood particles; applying a fluorescent tracer to an organic biocide; applying the organic biocide with the tracer to the plurality of wood particles; compressing the plurality of wood particles to form a composite wood product; subjecting the organic biocide and tracer treated composite wood product to an x-ray fluorescence analysis; determining concentration of the additive detected within the composite wood product; and determining concentration of the organic biocide within the composite wood product based on a correlation between the concentration of the additive detected and the concentration of the organic biocide within the composite wood product; wherein the correlation between the concentration of the tracer detected and the concentration of the organic biocide within the composite wood product is expressed by a coefficient of organic biocide retention K, wherein: K =( A 2 *Z 1 )/( A 1 *Z 2 ) wherein A 1 represents a target concentration of the organic biocide in one or more samples; wherein A 2 represents an assayed concentration of organic biocide in the one or more samples; wherein Z 1 represents a target concentration of the tracer element in the one or more samples; and wherein Z 2 represents an assayed concentration of the tracer element in the one or more samples; and wherein K is approximately 0.50.