187 *Corresponding author. E-mail: sandramaia@iq.ufrgs.br Fax: +55 5133087304 Atomic Spectroscopy Vol. 36(5), September/October 2015 INTRODUCTION Wood is employed for a variety of purposes due to its numerous advantages and utilities (1). One of the most important uses of wood is in construction, and particularly in the United States, Canada, Australia, and South Africa also for the manu- facture of utility poles. In Brazil, it is used for this purpose primarily in the southern part of the country (2). ABSTRACT To prevent the degradation of wood used for utility poles, a chromated copper arsenate (CCA) preservative is introduced to increase the wood’s resistance to degradation. The components of CCA are highly toxic and may leach into the environment, con- taminating the soil as well as sur- face and groundwater. The aim of the present study was to deter- mine the As, Cr, and Cu concen- tration in samples of CCA-treated wood poles using acid decompo- sition in closed flasks, oven heat- ing, and the ICP-MS technique. For this purpose, milled wood samples (particle size ≤425 μm) were decomposed in a mixture of concentrated HNO 3 and H 2 O 2 for 24 hours at 95 °C. The refer- ence material NIST SRM 1575a Trace Elements in Pine Needles was used to evaluate the accu- which has been used since the 1950s, is to-date the most widely applied wood preservative world- wide. It is accepted as one of the most effective treatments for pro- tection of wood against fungi, insects, and marine borers (7). In the CCA treatment process, wood products such as dimensional lumber, plywood, and poles are preserved by impregnating the wood with an aqueous solution containing CrO 3 , CuO, and As 2 O 5 in a pressurized treating cylinder. After addition of the preservative, the wood is removed from the cylinder and allowed to dry. Arsenic and copper act as biocides, and chromium acts as a “fixing” agent to bind the metals to the wood. The CCA fixation process refers to the chemical reactions that take place when hexavalent chromium is reduced to trivalent chromium in the wood (8). The composition of CCA is typi- cally 34% chromic oxide, 13% cupric oxide, 25% arsenic pentox- ide, and 28% water and inert mate- rials (9). From a commercial standpoint, CCA is an excellent alternative to increase wood durability, evidenced by numerous reports proving its efficiency. Nevertheless, from an environmental and public health perspective, its use is controversial due to its high toxicity. The compo- nents present in this preservative, particularly As and Cr, are highly toxic and several countries have restricted its use. These restrictions The biological origin of wood sets it apart from other industrial materials; however, its major draw- back is its tendency to decay (3–4). The agents responsible for deterio- ration can be physical, chemical, or biological in nature and include fac- tors such as heat, fire, pollution, humidity, climate effects, the pres- ence of highly acidic or basic sub- stances, friction with other materials and biological agents. Of these, bio- logical agents such as fungi, bacte- ria, and insects are considered the most harmful (5–6). The wood preservative of chro- mated copper arsenate (CCA), Determination of As, Cr, and Cu Concentrations in CCA-treated Wood Poles Using Acid Decomposition in Closed Flasks, Oven Heating, and ICP-MS Analysis Suzana F. Ferrarini a , Heldiane S. dos Santos a , Luciana G. Miranda a , Carla M.N. Azevedo a , Sandra M. Maia* b , Eduardo S. Chaves c , and Marçal J.R. Pires a a Programa de Pós-Graduação em Engenharia e Tecnologia de Materiais (PGETEMA), Pontifícia Universidade Católica do Rio Grande do Sul, Av. Ipiranga, 6681, 90619-900 Porto Alegre-RS, Brazil b Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre-RS, Brazil c Departamento de Engenharia Química, Universidade Tecnológica do Parana, Campus Ponta Grossa, Av. Monteiro Lobato, s/n - Km 041787/1788, 84016210 Ponta Grossa-PR, Brazil racy of the method, and the results obtained for As, Cr, and Cu were in agreement with the certified values. For the analysis of real samples, wood poles with different characteristics were used: poles submitted to impreg- nation under laboratory condi- tions, poles exposed to industrial treatment with preservatives, and poles removed from service. In the comparison of the results with those obtained for decom- position with microwave heat- ing, the paired t-test showed no significant difference between the two methods. In addition, linear regression of the data yielded a high R value and the slope of the regression close to 1 for all of the elements, indicat- ing that the proposed method is nearly identical with microwave heating for the determination of As, Cr, and Cu in wood pole sam- ples.