Analyte Certified Concentration Analyte Certified Concentration(pg/g) (pg/g)2,3,7,8-TCDD. 263 ± 53 1,2,3,7,8-PeCDF . 39 ± 14total TCDD .416 ± 121 2,3,4,7,8-PeCDF . 62 ± 321,2,3,7,8-PeCDD. 22 ± 8total PeCDF. 790 ± 489total PeCDD . 226 ± 1431,2,3,4,7,8-HxCD