Development of Certified Reference Materials of Plastics Containing Decabrominated Diphenyl Ether

A certified reference material (CRM, NMIJ CRM 8108-b) of polystyrene resin containing decabrominated diphenyl ether (DBDE) was developed. The form of the CRM was a disk with 30 mm diameter and 2 mm thickness. Homogeneity tests of the CRM disks by X-ray fluorescence spectrometry analysis indicated that the Br concentrations were almost constant both in a disk and among the disks. The DBDE concentration in CRM was determined by two analytical methods; GC-MS combined with the isotope dilution method (the primary method of measurement) and HPLC-UV detection using the standard addition method. The analytical results obtained by these two methods agreed within the uncertainty. Considering additional sources of uncertainty, such as the water content and stability, the concentration of DBDE in CRM was certified as 312 mg/kg, and its expanded uncertainty was 16 mg/kg with a coverage factor of k = 2.