Introduction In 1997, we reported PCDD and PCDF concentralions for 43 food items purchased from local stores in Mississippi, USA (1). The three farm-raised catfish samples had the highest 2,3,7,8-tetraCDD concentrations (2.5-8.8 pg/g lipid) and the highest I-TEQ (10.2-27.8 pg/g I-TEQ) of all food ilems (1). The farm-raised catfish also contained remarkably high concentrations of the higher chlorinated dioxins and most non-2,3,7,8-substituled PCDD congeners. Later, we purchased additional farm-raised catfish from the same manufacturer and catfish directly from farms in Mississippi, Arkansas, and Alabama. We also collected sediment from the Mississippi catfish ponds and catfish feed from the Mississippi and Arkansas farms. In 1998, we confirmed the results of our earlier study and found even higher 2,3,7,8-tetraCDD concentrations (32 and 27 pg/g lipid) and I-TEQ values (37-43 pg/g I-TEQ) in the two catfish from the Arkansas farm (2). In addition, our results clearly showed that the feed, and not the pond sediment, was the source of PCDDs lo the farm-raised catfish (2). We also reported the results of our analyses of the catfish feed, including each of the eight components ofthe feed (3). One ofthe catfish feed ingredients-the soybean meal-had extraordinarily high concentrations of all 2,3,7,8-substituted PCDDs and an I-TEQ value of 576 pg/g fal. Moreover, the congener pattern and the high S PCDDs/E PCDFs ratio for the soybean meal were unique; no environmental samples, chemical producis, or known anthropogenic sources of PCDDs and PCDFs had a similar pattem or ratio. As a result, we suggested natural formation could be the source of PCDDs in the soybean meal (3). Our results were later confirmed by Ferrario et al. who further determined that a ball clay added to the soybean meal was the primary source of PCDDs in the catfish feed (4). The United States Food and Drug Administration (US FDA) confirmed the ball clay was the source of PCDDs lo the catfish feed and also found that the same soybean meal was a component in chicken feed (5). Hayward et al. also found PCDD patterns in chicken eggs that resembled the PCDD patterns in farm-raised catfish feed (6). At Dioxin 2000, we presenled PCDD and PCDF concentrations for four U.S. ball clay samples, three U.S. kaolin samples, and one German kaolin sample (7). In this study, we report PCDD and PCDF concentrations for four additional German kaolin samples, which confirm our earlier results. Methods and Materials In April, 2000, we obtained four kaolin samples from Germany. Seventeen internal standards were added to each sample, each sample was then Soxhlet-extracted with 150 mL of toluene. The extracts were purified first in a multistep silica column, followed by a basic alumina column. The final clean-up was made on a Carbopack/Celite column. The final extracts were evaporated in 30 pL of letradecane. HRGC/HRMS analyses was performed on each sample with a 60 m JW DB-5 column directly attached to a VG instrument (70/70S). ORGANOHALOGEN COMPOUNDS