FORMATION OF POLYCHLORINATED DIBENZO-p-DIOXINS DURING THE EXTRACTION OF PENTACHLOROPHENOL-CONTAMINATED GUAR GUM
During the extraction of pentachlorophenol-contaminated guar gum, significant biases are observed when acetone is used either as a solvent or part of a mixture of solvents. These biases may be up to five times the consensus TEQ values, or six times that of the major TEQ contributor, HpCDD. Even the small amount of acetone used during the spiking step can result in a significant bias; e.g., +50 percent for OCDD, and +10 percent for the WHO-1998 TEQ (five times the error). The postulated mechanism for the formation of PCDDs implicates precursor molecules such as polychlorinated hydroxydiphenylethers (a.k.a. predioxins). The role of acetone is through the acid-catalyzed formation of the enol form. The latter becomes a receptor for HCl, which is intramolecularly eliminated from the predioxin isomers/congeners with the hydroxyl and chlorine groups in ortho positions. The significance of this observation in PCP-contaminated environmental samples is assessed.
Yves Tondeur Bryan Vining Allen Martin Jeremy Morgan Jerry Hart
Analytical Perspectives,Wilmington,NC 28405,USA Analytical Perspectives,Wilmington,NC 28405,USA University of North Carolina in Wilmington,NC 28405, University of North Carolina in Wilmington,NC 28405,USA
国际会议
北京
英文
1-4
2009-08-24（万方平台首次上网日期，不代表论文的发表时间）