Analysis Method of Polybrominated Diphenyl Ethers Using GC-MS and GC-MS/MS Coupled With an Automated Identification and Quantitation System with a Database

There are 209 isomers of polybrominated diphenyl ether (BDEs) with each one showing different level of toxicity and detection frequency in environmental samples. GC-MS is commonly used for the analysis of BDEs.
A common method of BDEs analysis requires the expensive standards and instrument of gas chromatograph/ double focusing high resolution magnetic sector mass spectrometer (GC-HRMS). Moreover, the handling and maintenance of GC-HRMS instruments is a time-consuming and labor-intensive work. This situation is critical problem especially for environmental laboratories in under developing countries.
Kadokami et al. [1] developed a novel automated identification and semi-quantification system with a database (AIQS-DB) which allows an automatic identification and semi-quantitation of 1,000 pollutants without standard sample analysis. The database includes retention indices, mass spectra, and internal calibration curves for 1,000 pollutants. The pollutants are identified using the mass spectrum and retention time predicted by retention index and retention times of n-alkanes. Semi-quantitation is performed using internal calibration curve.
We developed a method for BDEs analysis. For reduction of the necessary authentic standard, AIQS-DB was applied to BDEs with less toxicity and detection frequency, while the conventional method (isotope dilution method) was applied to BDEs with a higher toxicity and detection frequency in order to obtain precise quantitation results. For easy handling and maintenance, single quadrupole mass spectrometer of GC-MS was used.
The developed method was applied to sediment samples. BDEs were detected and semi-quantitation results were obtained. However, several samples with heavy matrix could not detected BDEs due to peak overlapping. GC-MS was not applied to heavy matrix sample analysis such as sediment sample. Gas chromatography triple quadrupole mass spectrometry (GC-MS/MS) was applied to improve the separation of BDEs from heavy matrix, ensuring easy handling and maintenance. Using GC-MS/MS, BDEs were successfully identified and determined, corresponding to the results by the conventional method by HR-GCMS.