title: 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 (OH-monoBDE) 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 pre-ionization 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 post-ionization 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 two-dimensional 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.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Ma
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Bai
authors.forename: Hai-Wei
authors.initials: HW
authors.lastname: Xi
authors.forename: Guang-Cheng
authors.initials: GC
authors.lastname: Xi
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Ren
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.forename: Liang-Hong
authors.initials: LH
authors.lastname: Guo
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D055768:Halogenated Diphenyl Ethers / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D057927:Hydrophobic and Hydrophilic Interactions; D006900:Hydroxylation; D013058:Mass Spectrometry / Q000379:methods*; D008970:Molecular Weight
chemical_list: D055768:Halogenated Diphenyl Ethers