ABSTRACT
Contents 40.1 Introduction ................................................................................................................. 798 40.2 Sample Pretreatment and Recovery Studies .................................................................. 799
40.2.1 Sample Storage ................................................................................................ 799 40.2.2 Spiking and Recovery Studies ......................................................................... 799
40.3 Extraction Methods ..................................................................................................... 800 40.3.1 Soxhlet Extraction ........................................................................................... 800 40.3.2 Solid Phase Extraction and Matrix Solid Phase Dispersion ............................. 800 40.3.3 Supercritical Fluid Extraction ..........................................................................801 40.3.4 Accelerated Solvent Extraction .........................................................................801 40.3.5 Microwave Oven ............................................................................................. 802
40.4 Cleanup Methods ......................................................................................................... 802 40.4.1 Lipid Removal ................................................................................................. 803 40.4.2 Isolation of Uncommon Chemical Interferences ............................................. 803
40.5 Fractionation/Group Separation ................................................................................... 803 40.6 Automation of Extraction and Cleanup ........................................................................ 804 40.7 Instrumental Determination ........................................................................................ 805
40.7.1 GC Congener Separation ................................................................................ 805 40.7.2 GC Detectors .................................................................................................. 807
40.8 Bioanalytical Screening Methods ................................................................................. 808 References ............................................................................................................................... 809
40.1 Introduction Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), two groups of Persistent Organic Pollutants (POPs), are structurally related chlorinated aromatic hydrocarbons which are generally referred to as “dioxins.” ey are of great concern due to the extreme toxicity of the 2,3,7,8 chlorine substituted congeners and their presence in all compartments of the environment. PCDD/Fs are formed as by-products of a wide variety of chemical industry and combustion processes that contain chlorine and chlorinated aromatic hydrocarbon sources [1]. Due to their low water solubility, hydrophobicity, and resistance to degradation, these substances are found in a wide range of biological samples, and tend to accumulate in animal and human adipose tissues through the food web [2]. Among the 210 possible congeners, seven 2,3,7,8-substituted PCDDs and 10 PCDFs are generally considered the most persistent and toxic PCDD/F congeners, since they have toxic properties similar to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which is the most toxic congener of these compounds [3-5].
