Chromatographic and Ionization Properties of Polybrominated Diphenyl Ethers Using GC/High-Resolution MS with Metastable Atom Bombardment and Electron Impact Ionization

Abstract

The chromatographic and ionization properties of 35 polybrominated diphenyl ether (PBDE) congeners were investigated using GC/HRMS with metastable atom bombardment (MAB) and electron impact (EI) ionization. A multiple linear regression model based on bromine substitution patterns and MOPAC calculated physical properties was developed to predict relative GC retention times of individual PBDE congeners. Although five different sources of metastable rare gas atoms (He, N2, Ar, Xe, and Kr) were investigated with MAB ionization, only MAB-N2 provided adequate ionization efficiency and predictability. Because of reduced background noise to the MS detector, MAB-N2 had a lower limit of detection for tetra- and penta-BDEs than EI, despite having a lower sensitivity. Using MAB-N2, the molecular ion was always the base peak, with little fragmentation taking place. Conversely, using EI ionization, the [M - nBr]+ peak (where n = 1-4, depending on the number of Br substituents) was the dominant ion for all PBDE congeners. Multiple linear regression models representing the molecular ion response of PBDE congeners analyzed by GC/ HRMS with MAB-N2 and EI ionization were also developed using the number and type of Br substituents and ionization potentials. A significantly higher level of predictability was obtained for the MAB-N2 response model than for EI.

Application of mass spectrometry in the analysis of polybrominated diphenyl ethers

“…GC/HRMS was also operated in other ionization modes. Ikonomou and Rayne (2002) investigated the chromatographic and ionization properties of 35 PBDEs (BDEs 1, 2, 3, 10, 7, 11/8, 12, 13, 15, 30, 32, 17, 25, 33/28, 35, 37, 75, 49, 71, 47, 66, 77, 100, 119, 99, 116, 85, 155, 154, 153, 140, 138/166) using GC/HRMS with metastable atom bombardment (MAB), which was compared with EI ionization. Five different sources of metastable rare gas atoms (He, N 2 , Ar, Xe, and Kr) were investigated with MAB ionization, but only MAB‐N 2 provided adequate ionization efficiency and predictability.…”

Development of quantitative structure gas chromatographic relative retention time models on seven stationary phases for 209 polybrominated diphenyl ether congeners

“…QSRRs have been developed for a number of halogenated organic contaminant groups [14][15][16][17]. For PBDEs, Rayne and Ikonomou presented several predictive equations with five or seven simple parameters, including the numbers of ortho, meta, and para substituents, as well as molecular mass and calculated ionization potential and dipole moment, as independent variables [18][19][20]. The reliability of equations was examined by using basic statistics such as R 2 and F values rather than the predictions of relative retention times (RRTs) for PBDE congeners, which were not involved in model development.…”

Gas chromatography/ion trap mass spectrometry applied for the determination of polybrominated diphenyl ethers in soil

“…PBDEs have been analyzed by gas chromatography coupled with various mass spectrometric techniques 12, 16, 19, 23, 34–42. Recently, a draft method using HRGC/HRMS for the determination of PBDEs was issued by the US EPA (EPA Draft Method 1614).…”