CERTIFICATION OF THE CONTENTS OF 5 POLYCHLORODIBENZO-P-DIOXINS AND 6 POLYCHLORODIBENZO FURANS IN MILK POWDER

Preparation, homogeneity and stability studies of a natural milk powde r material and subsequent certification of the mass fraction of five p olychlorodibenzo-p-dioxins (D48, D54, D66, D67, D70) and six polychlor odibenzo furans (F83, F94, F114, F118, F121, F130) are described. The material, CRM 607, is intended for use in the method validation and qu ality control of the complete analytical procedure for congener-specif ic determination of dioxins in milk powder and similar dairy products and was certified in an interlaboratory study for: 2,3,7,8-TCDD, 0.25 ng/kg; 1,2,3,7,8-PeCDD, 0.79 ng/kg; 1,2,3,4,7,8-HxCDD 0.42 ng/kg; 1,2, 3,6,7,8-HxCDD, 0.98 ng/kg; 1,2,3,7,8,9-HxCDD, 0.34 ng/kg; 2,3,7,8-TCDF , 0.05 ng/kg; 1,2,3, 7,8-PeCDF, 0.054 ng/kg; 2,3,4,7,8-PeCDF, 1.81 ng/ kg; 1,2,3,4,7, 8-HxCDF, 0.94 ng/kg; 1,2,3,6,7,8-HxCDF, 1.01 ng/kg and 2,3,4,6,7,8-HxCDF, 1.07 ng/kg. An indicative (non-certified) value was assigned to the mass fraction of the hepta-and octachlorinated congen ers D73, D75, F131, F134, F135 and the HxCDF F124.