López P, Brandsma S A, Leonards P E G, De Boer J
Institute for Environmental Studies (IVM), VU University Amsterdam, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands.
J Chromatogr A. 2009 Jan 16;1216(3):334-45. doi: 10.1016/j.chroma.2008.08.043. Epub 2008 Aug 15.
Brominated flame retardants (BFRs) are the chemicals of high importance within the REAch framework. In addition to polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA), other BFRs such as bromophenols, intermediates in FR formulation like bromoanilines, and their brominated and non-brominated by-products such as bromoanisoles, bromotoluenes, bromoalkanes and 1,5,9-cyclododecatriene, respectively should be monitored and controlled because of their toxicity and their very low odour and taste thresholds, below sub-nanogram-per liter levels. In the present study several analytical methods for the simultaneous determination, i.e., combining one single sample treatment and one analysis step, of these compounds in water have been developed, optimized and evaluated. The methods involve a (pre-concentration)-extraction technique, such as liquid-liquid (LLE), solid-phase (SPE), headspace (HS) extraction or solid-phase microextraction (SPME), followed by gas chromatography (GC)-mass spectrometry (MS) analysis with either electron capture negative ionization (ECNI) or electron impact (EI) as ionization techniques. ECNI is more sensitive than EI for analytes with more than one bromine atom. HS and SPME were previously optimized by means of a multifactorial experimental design. Extraction temperature and the liquid/headspace volume ratio were the most significant factors in HS extraction. In SPME, the variables studied were the nature of the fiber, the mode of extraction and the extraction temperature. Polydimethylsiloxane (PDMS) fibers appeared to be more suitable than carboxen-polydimethylsiloxane (CAR-PDMS) for the analysis of the target compounds with more than one bromine atom. The extraction of 2,4-dibromoaniline was only achieved in a direct immersion mode, in which the optimal extraction temperature was 60 degrees C. The methods LLE-GC-(ECNI)MS, LLE-GC-(EI)MS, SPE-GC-(ECNI)MS, SPE-GC-(EI)MS, HS-GC-(EI)MS and SPME-GC-(EI)MS were evaluated in terms of linearity, precision, detection limits and trueness. All methods, with the exception of HS-GC-(EI)MS, were linear in a range of at least two orders of magnitude, giving recoveries above 75% and detection limits at the low ng/L level for most of the target analytes. SPE-GC-(ECNI)MS is the most sensitive and reliable method for the determination of most of the bromine compounds, whereas SPE-GC-(EI)MS is the most suitable to quantify the three isomers of 1,5,9-cyclododecatriene. Both methods together with SPME-GC-(EI)MS (for qualitative confirmation) were applied to water samples from the Western Scheldt (The Netherlands), where 2,6-dibromophenol and 2,4,6-tribromoanisole could be detected at levels higher than their respective odour thresholds.
溴化阻燃剂（BFRs）是《化学品注册、评估、授权和限制法规》（REAch）框架内极为重要的化学品。除了多溴二苯醚（PBDEs）、六溴环十二烷（HBCD）和四溴双酚A（TBBPA）之外，其他溴化阻燃剂，如溴酚、阻燃剂配方中的中间体（如溴苯胺），以及它们的溴化和非溴化副产物，如溴苯甲醚、溴甲苯、溴代烷烃和1,5,9 - 环十二碳三烯，因其毒性以及极低的气味和味道阈值（低于每升亚纳克水平），都应受到监测和控制。在本研究中，已开发、优化并评估了几种用于同时测定水中这些化合物的分析方法，即通过单一的样品处理和一个分析步骤来实现。这些方法包括一种（预浓缩）-萃取技术，如液液萃取（LLE）、固相萃取（SPE）、顶空萃取（HS）或固相微萃取（SPME），随后采用气相色谱（GC）-质谱（MS）分析，以电子捕获负离子化（ECNI）或电子轰击（EI）作为电离技术。对于含有多个溴原子的分析物，ECNI比EI更灵敏。HS和SPME先前已通过多因素实验设计进行了优化。萃取温度和液/顶空体积比是HS萃取中最重要的因素。在SPME中，所研究的变量包括纤维的性质、萃取模式和萃取温度。对于分析含有多个溴原子的目标化合物，聚二甲基硅氧烷（PDMS）纤维似乎比碳分子筛-聚二甲基硅氧烷（CAR-PDMS）纤维更合适。2,4 - 二溴苯胺的萃取仅在直接浸入模式下才能实现，其中最佳萃取温度为60℃。对LLE-GC-(ECNI)MS、LLE-GC-(EI)MS、SPE-GC-(ECNI)MS、SPE-GC-(EI)MS、HS-GC-(EI)MS和SPME-GC-(EI)MS这几种方法的线性、精密度、检测限和准确性进行了评估。除HS-GC-(EI)MS外，所有方法在至少两个数量级的范围内呈线性，大多数目标分析物的回收率高于75%，检测限处于低纳克/升水平。SPE-GC-(ECNI)MS是测定大多数溴化合物最灵敏、最可靠的方法，而SPE-GC-(EI)MS最适合定量1,5,9 - 环十二碳三烯的三种异构体。这两种方法以及SPME-GC-(EI)MS（用于定性确认）被应用于荷兰西斯海尔德河的水样分析，在那里检测到2,6 - 二溴酚和2,4,6 - 三溴苯甲醚的含量高于其各自的气味阈值。
