Total mercury determination in different tissues of broiler chicken by using cloud point extraction and cold vapor atomic absorption spectrometry A.Q. Shah, T.G. Kazi * , J.A. Baig, H.I. Afridi, G.A. Kandhro, M.B. Arain, N.F. Kolachi, S.K. Wadhwa Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan article info Article history: Received 20 June 2009 Accepted 11 September 2009 Keywords: Mercury Tissues Broiler chicken Cloud point extraction Cold vapor atomic absorption spectrometry abstract A cloud point extraction (CPE) method has been developed for the determination of total mercury (Hg) in different tissues of broiler chicken by cold vapor atomic absorption spectrometry (CVAAS). The broiler chicken tissues (leg, breast, liver and heart) were subjected to microwave assisted digestion in a mixture of nitric acid and hydrogen peroxide (2:1 ratio), prior to preconcentration by CPE. Various parameters such as the amount of ammonium O,O-diethyldithiophosphate (DDTP), concentrations of Triton X-114, equilibrium temperature, time and centrifugation have been studied in order to find the best conditions for the determination of mercury. For validation of proposed method a certified reference material, DORM-2 was used. No significant difference p > 0.05 was observed between the experimental results and the certified values of CRM (paired t-test). The limit of detection and quantitation obtained under the optimal conditions were 0.117 and 0.382 lg/kg, respectively. The accumulation of Hg in different tis- sues were found in the order of, liver > muscles > heart. The concentration of Hg in chicken tissues were found in the range of 1.57–2.75, 1.40–2.27, 1.55–4.22, and 1.39–2.61 lg/kg in leg, breast, liver and heart, respectively. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Mercury is one of the element with the highest environmental risk and it is considered a global pollutant, as a result of both nat- ural origin and anthropogenic activities (Aranda et al., 2008; Tuzen and Soylak, 2005). Elemental Hg is used in several applications, such as electrical devices, lamps, batteries and dental amalgam (Collasiol et al., 2004). The concentration of Hg in the environment is also due to the combustion of coal and fuel oil, resulting in the emission of considerable amounts of Hg to the atmosphere (Boening, 2000; Falandysz et al., 2000). The important sources of Hg in the agricultural ecosystems were the mercury seed dressings, the production of which was discontinued in Poland in 1978 while in the Czech Republic they were still used at the beginning of the nineties. Mercury is a constant component of municipal sewage, which may used as soil conditioner and agricultural fertilizer, cre- ates a serious danger of introducing this heavy metal into food products and feeds for farm animals (Tuzen et al., 2009a; Zarski et al., 2003). The ability of Hg to accumulate in tissues of animal’s organisms might be influence the food chain (Ingrid et al., 2007). Mercury can also be readily absorbed by the human body when in- haled by mucous membranes, mainly damaging the central ner- vous system (Collasiol et al., 2004). Some poisonous hydrophobic compounds of mercury can cross biological membranes easily and concentrate in the blood and have an immediate and perma- nent effect on the brain and central nervous system (Mondal et al., 2001). The toxicological implications of the mercury contents in the environments have encouraged the development of very sensitive methods for its determination. However, mercury is at such a low concentration in the environmental and biological samples that the determination of mercury requires an enrichment step (Ferrua et al., 2007; Tuzen et al., 2009b). The CPE is an interesting alterna- tive to conventional solvent extraction because it produces high extraction efficiencies and concentration factors and uses inexpen- sive, non-toxic reagents (Daveiga et al., 2003; Tuzen et al., 2009; Zhu and Wang, 2006; Silva et al., 2006). The purpose of this study was to determine the total mercury in different tissues of boiler chicken frequently consumed as major diet by all population in Pakistan as well as other countries. The mercury was extracted as DDTP complex mediated by non-ionic surfactant Triton X-114. Under the optimal conditions, the Hg in non-ionic surfactant-rich phase was determined by using cold va- por atomic absorption spectrometry (Wuilloud et al., 2002, 2001; Capelo et al., 2004; Torres et al., 2005). All significant variables were studied including surfactant and complexing reagent concen- trations, equilibrium temperature and time. The proposed method 0278-6915/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.fct.2009.09.016 * Corresponding author. Tel.: +92 022 2771379; fax: +92 022 2771560. E-mail addresses: aqshah07@yahoo.com (A.Q. Shah), tgkazi@yahoo.com (T.G. Kazi), jabmughal@yahoo.com (J.A. Baig), hassanimranafridi@yahoo.com (H.I. Afridi), gakandhro@yahoo.com (G.A. Kandhro), bilal_ku2004@yahoo.com (M.B. Arain), nidafatima6@gmail.com (N.F. Kolachi), shamlect@gmail.com (S.K. Wadhwa). Food and Chemical Toxicology 48 (2010) 65–69 Contents lists available at ScienceDirect Food and Chemical Toxicology journal homepage: www.elsevier.com/locate/foodchemtox