Athanasiadou Maria, Marsh Göran, Athanassiadis Ioannis, Asplund Lillemor, Bergman Ake
Department of Environmental Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden.
J Mass Spectrom. 2006 Jun;41(6):790-801. doi: 10.1002/jms.1035.
Twenty-six methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were characterized by gas chromatography (GC) on four different GC columns with different lengths and polarities, as well as by mass spectrometry using three ionization techniques, electron ionization (EI), electron capture negative ionization (ECNI) and positive ion chemical ionization (PICI). MeO-PBDE congeners with similar retention times on a nonpolar GC column were separated when analyzed on a polar GC column. EI can be used to determine the position of the methoxy substituent (ortho, meta or para) relative to the diphenyl ether oxygen in the MeO-PBDEs. The PICI ionization technique is shown to be valuable to generate structural information of the MeO-PBDEs, i.e. the degree of bromination on both the methoxy-substituted ring and the entirely brominated phenyl ring can be obtained. This structure information can also be achieved for certain MeO-PBDEs with the methoxy group in ortho position to the diphenyl ether bond in ECNI mode. Like other brominated compounds ECNI is preferable when analyzing environmental samples for quantification of MeO-PBDEs because of the formation of bromide ions, which enables low detection limits.
采用气相色谱法（GC）在四根不同长度和极性的气相色谱柱上对26种甲氧基多溴二苯醚（MeO-PBDEs）进行了表征，并采用电子电离（EI）、电子捕获负离子化（ECNI）和正离子化学电离（PICI）三种电离技术通过质谱法进行分析。在非极性气相色谱柱上保留时间相似的MeO-PBDE同系物，在极性气相色谱柱上分析时可实现分离。EI可用于确定MeO-PBDEs中甲氧基取代基相对于二苯醚氧的位置（邻位、间位或对位）。结果表明，PICI电离技术对于生成MeO-PBDEs的结构信息很有价值，即可以获得甲氧基取代环和全溴化苯环上的溴化程度。对于某些甲氧基位于二苯醚键邻位的MeO-PBDEs，在ECNI模式下也可以获得这种结构信息。与其他溴化化合物一样，在分析环境样品以定量MeO-PBDEs时，ECNI是首选，因为会形成溴离子，从而实现低检测限。
