Wood treatments are used to protect lumber from fungi, insects, UV damage and general wear. Common wood treatment formulations containing only Cu, CCA, Penta and ACZA. Ammonia Copper Zinc Arsenate (ACZA) is often used to treat wood species that do not easily retain other treatments, such as Douglas Fir. When treating wood, the proper balance of treatment solution must be monitored to ensure the highest quality while minimizing waste and excess cost due to treatment usage or product rejection. Cu, Zn and As levels are monitored in solution prior to treatment, and then in the wood to ensure proper retention. A quick, simple, reliable means of analysis is required throughout the quality control process. XRF is an ideal tool for such analysis.