Introduction 1 2 3 http://www.bsef.com 4 5 6 11 9 12 13 6 9 14 16 Injection techniques 17 1 5 Fig. 1 BDE 17  18 20 17 21 23 14 24 26 25 1 25 Table 1 PBDE 25 Parameter Domain  Injection rate 300 μl/min Injection temperature 80 °C Vent flow 150 ml/min Temperature rate 700 °C/min Transfer temperature 325 °C Transfer time 0.3–0.6 min Solvent elimination time 0.1 min Carrier gas pressure 650 kPa 26 27 27 28 GC column selection 17 17 17 2 24 25 Fig. 2 n error bars 17  29 2 29 30 ortho meta para Table 2 63 Column DB-1 DB-5 HT-5 DB-17 DB-XLB HT-8 CP-Sil 19 Dimension (m × mm × μm) 30 × 0.25 × 0.25 30 × 0.25 × 0.25 30 × 0.25 × 0.10 30 × 0.25 × 0.25 30 × 0.25 × 0.25 25 × 0.22 × 0.25 17 × 0.15 × 0.30 Number of coeluting BDEs 62 63 66 67 56 62 72 Number of coelutions with flame retardants 24 26 27 30 22 26 29 Co-elution with major BDE congeners Major BDE  28 16, 33 16, 33 16, 33, 38   16, 33, 38 16, 33  47         49 68, 80 68 68 62 42, 48, 68, 71 68 51, 75  85    155   114  99   116 127     100   109 101  109, 120   138   166  HBCD  166  153   HBCD 168     154 MTBBP-A, BB-153 MTBBP-A, BB 153  105  126 BB 153  183 BB 169 BB 169      MTBBP-A HBCD Chromatographic interferences 29 6 9 29 31 31 2 + 2 + m m 32 34 − 79 81 3 32 34 − 4 2 35 37 4 2 4 Fig. 3 MeO-BDE GC ECNI MS PDBE  Fig. 4 DBP-Br 4 Cl 2  Calibration and quantification standards 38 40 13 13 13 41 42 5 20 5 13 Fig. 5 a b  Detection techniques 31 m m 43 45 19 46 47 2 + − − m z 48 14 33 49 50 x y − 79 81 13 6 5 − 51 48 50 52 13 49 53 16 54 + 2 + + 54 ortho 55 56 56 Alternate analytical techniques 57 + 2 + + 2 + 58 60 61 62 63 55 Challenges in PBDE analyses 64 5 65 66 67 68 69 70 38 39 71 73 40 74 29 75 With the implementation of the European Union’s directive on waste electrical and electronic equipment and on the restriction of the use of certain hazardous substances (including PBDEs) in electrical and electronic equipment (RoHS; 2002/95/EC), fast and reliable methods for determining PBDE content in electrical equipment will be needed to ensure compliance. The use of X-ray fluorescence (XRF) portable analyzers is a promising method that would allow measurement of the total bromine content of a plastic component by scanning its surface with the handheld device. Obviously there will be difficulties in determining which type of brominated flame retardants are present in materials analyzed with this instrument. However, the XRF may be useful for determining if PBDE degradation occurs after exposure to light and it may be possible to determine the percentage of bromine lost through this pathway in an easy and fast method. Future directions in PBDE research may also wish to examine the fate of the bromine atoms that could be lost from PBDEs via the aforementioned degradation/debromination processes. Conclusions In conclusion, a variety of methods are now available to accurately and precisely measure a suite of PBDE congeners in environmental samples. The choice of method selection will involve a compromise between cost, selectivity and sensitivity, particularly since different congeners require different instrumental optimization techniques, especially BDE 209. The Environmental Protection Agency has outlined a protocol for measuring PBDEs (EPA method 1614), but to the author’s knowledge, this method is still in draft form.