Trace Analysis of Brominated Flame Retardants with High Resolution GC–MS

Polybrominated diphenyl ethers (PBDEs) are among the most important and widely used flame retardants. Recent legislation banned certain PBDE congeners.¹ EU directive 2003/11/EC prohibits the use of Penta-BDE and Octa-BDE for the member states of the European community.² Therefore, analysis of PBDEs have received increased interest as a result of their known toxicity.

The most efficient trace analysis technique for BFRs proved to be high resolution GC–MS using an isotope dilution technique for quantification, especially suited for metabolism and accumulation studies in biological matrices.

Table 1: GC parameters.

Experimental Conditions

All measurements were performed on the DFS high resolution GC–MS coupled to a TRACE GC Ultra gas chromatograph with split/splitless injector. Samples were injected using the TriPlus autosampler.

GC column: Thermo TRACE TR-5MS, 15 m, 0.25 mm i.d., 0.1 μm film.

Injection volume: 1 μL of each sample.

GC temp. programme: see Table 1.

MS resolution: 10 000 (10% valley definition).

MID acquisition: one quantification and one ratio confirmation mass each, detailed MID set-up (see Table 1).

Internal standards: ¹³C labelled PBDE standards.

Analytical standards: Wellington Laboratories (not containing Octa- and Nona-BDEs).

Autotuning for the highest sensitivity was performed on PFK mass 480.9688.

PFK is also used as an internal mass reference providing a specific lock and calibration mass for each MID window (see Table 2). In every single MID measurement cycle, the instrument automatically performs an electric mass calibration taking these two reference masses as calibration points.

Table 2: MID set-up, MID lock mode (masses in brackets; optional second ratio mass for native PBDE).

Results

All congeners in the employed PBDE standard can be separated on the 15 m TRACE TR-5MS column (Figure 1) in the order of their bromination degree. The use of a short 15 m column with a thin film is recommended to analyse the thermolabile Deca-BDE.

Figure 1

The limits of quantification (LOQs) for the far higher boiling PBDEs are similar to those achieved for dioxin and PCBs. The quantification shows excellent linearity from the lowest fg range up to the highest standards (Figure 2).

Using the DFS high resolution GC–MS, polybrominated diphenyl ethers (PBDE) can be analysed with highest selectivity providing LOQs in the low femtogram range with the same analytical certainty as required in the analysis of dioxins and PCBs. For further information please visit www.thermo.com/dfs

Figure 2

Thermo Electron (Bremen) GmbH

Hanna-Kunath-Strasse 11, 28199 Bremen, Germany

tel. +49 421 5493-0

fax +49 421 5493-396

e-mail: hans-joachim.huebschmann@thermo.com

website: www.thermo.com

Reference

1. California Legislature Bill No. 302, Chaptered 11 August, 2003.

2. European Parliament and Council Directive 2002/95/EC on the Restriction of Hazardeous Substances (RoHS). European Parliament and Council Directive 2002/96/EC on Waist Electrical and Electronic Equipment (WEEE).