RETRACTED: Preconcentration and solid phase extraction method for the determination of Co, Cu, Ni, Zn and Cd in environmental and biological samples using activated carbon by FAAS

This article has been retracted at the request of the Editor-in-Chief. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).Reason: Considerable concern was raised about the research purportedly conducted at Sri Venkateswara University, India with the alleged involvement of Prof. P. Chiranjeevi.Questions were raised as to the volume of publications, the actual capacity (equipment, orientation and chemicals) of the laboratory in which Prof. Chiranjeevi worked, the validity of certain of the research data identified in the articles, the fact that a number of papers appear to have been plagiarized from other previously published papers, and some aspects of authorship.Professor Chiranjeevi was given the opportunity to respond to these allegations. Thereafter, a committee was constituted by the University to look into these allegations. Based on the enquiry committee report, we have been informed by the head of the Department of Chemistry at Sri Venkateswara University that the university authorities have taken disciplinary action against Prof.Chiranjeevi, as the university considers that there are grounds for such action.Therefore, based on the results of this investigation, the Editor-in-Chief is retracting this article.