Wood treatments are used to protect lumber from fungi, insects, UV damage and general wear. Lumber treated with copper or copper oxide is used in a variety of residential and commercial construction projects, including house and building foundations, fences, patio decks and playground playscapes. 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 or CuO 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.