Quality assurance/quality control procedures for chlorinated hydrocarbons in human breast adipose tissue

Extensive literature exists supporting the accumulation of organochlorine pesticides such as DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane], and polychlorinated biphenyls (PCBs) in human adipose tissue. Debate has surfaced concerning the link between these environmental contaminants and human breast cancer. Accurate residue analysis and proper analytical procedures are critical in determining the extent to which these compounds play a role in human breast cancer. Further, adequate quality assessment/quality control (QA/QC) is critical for reliable residue analysis. The purpose of this research was twofold: (1) to find an appropriate surrogate for human breast adipose tissue for spiking purposes, as human samples are difficult to obtain, and (2) to develop a human breast adipose tissue pool that yields adequate reproducibility with low coefficients of variation (CVs) for each compound of interest. Using a previously validated method developed in the Analytical Laboratory at Colorado State University, rendered ovine adipose tissue was found to be a suitable spiking material, as it was free of interfering compounds and behaved in a manner similar to human breast adipose tissue throughout the analytical method. Further, this analytical method was used to produce data on three control pool preparations: (A) blended human breast adipose tissue (n = 26), (B) blended and partially rendered human breast adipose tissue (n = 12), and (C) fully blended and rendered human breast adipose tissue (n = 15). The CVs between control pools vary up to 20% for a single compound. The most reproducible preparation procedure requires full blending and rendering.