Comprehensive Two-Dimensional Separation of Hydroxylated Polybrominated Diphenyl Ethers by Ultra-Performance Liquid Chromatography Coupled with Ion Mobility-Mass Spectrometry

Abstract

A comprehensive two-dimensional system coupling ultra-performance liquid chromatography (UPLC) and ion mobility-mass spectrometry (IM-MS) has been applied for the separation and analysis of hydroxylated polybrominated diphenyl ethers (OH-PBDEs). A complex mixture containing 23 OH-PBDE congeners ranging from hydroxylated monobromodiphenyl ether (OHmonoBDE) to hydroxylated octabromodiphenyl ether (OH-octaBDE) was satisfactorily separated within 16 min of analysis time. The first-dimensional reversed-phase UPLC was performed on a sub-2 μm BEH C 18 chromatographic column using acetonitrile-water gradient elution program with a flow rate ramp. It enabled excellent chromatographic separation for both between-class and within-class OH-PBDEs based on their differences in hydrophobicity. Following the preionization resolution in the first dimension, the second-dimensional IM-MS employed a hybrid electrospray quadrupole ion mobility time-of-flight mass spectrometer and added an extra postionization separation for between-class OH-PBDE congeners on account of their relative mobility disparity during a very short period of 8.80 ms. The orthogonality of the developed twodimensional system was evaluated with the correlation coefficient of 0.9665 and peak spreading angle of 14.87°. The peak capacity of the system was calculated to be approximately 2 and 15 times higher than that of the two dimensions used alone, respectively. The two-dimensional separation plane also contributed to the removal of background interference ions and the enhanced confidence in the characterization of OH-PBDEs of interest.

Emerging environmental pollutants hydroxylated polybrominated diphenyl ethers: From analytical methods to toxicology research

“…( a ) and ( b ) are reprinted with permission from Zhai et al (2014) Copyright (2014) American Chemical Society. ( c ) and ( d ) are reprinted with permission from Ma et al (2011) Copyright (2011) American Chemical Society. GC‐MS, gas chromatography–mass spectrometry; OH‐PBDE, hydroxylated polybrominated diphenyl ethers.…”

“…Together with retention times and m / z values, the approach could improve the confidence in metabolite identification. Ma et al (2011) have developed a two‐dimensional LC‐IM‐MS for targeted analysis of OH‐PBDE congeners. The peak capacities and signal‐to‐noise ratios were significantly improved, background interference ions were substantially removed.…”

Advances in Instrumental Analysis of Brominated Flame Retardants: Current Status and Future Perspectives

“…Following the preionization resolution in the first dimension, the second-dimensional IM-MS employed a hybrid electrospray quadrupole ion mobility time-of-flight mass spectrometer and added an extra postionization separation for between-class OH-PBDE congeners on account of their relative mobility disparity during a very short period of 8.8 ms. The two-dimensional separation plane also contributed to the removal of background interference ions and the enhanced confidence in the characterization of OH-PBDEs of interest [ 133 ].…”

Comprehensive two-dimensional separation for the analysis of alkylphenol ethoxylates employing hydrophilic interaction chromatography coupled with ion mobility-mass spectrometry

“…Currently, LC in conjunction with ion mobility-mass spectrometry (IM-MS) is becoming increasingly popular for complex mixture analysis, due to complementary separation steps and elevated peak capacity. The applications include the analysis for environmental pollutants [38], rat urinary metabonome [39], human plasma proteome [40], peptide mixtures [41], pharmaceutical formulation [42], etc. The principle for IM-MS has been described in detail elsewhere [43].…”