Improved GC/ECNI-MS sensitivity of decabromodiphenyl ether determination on 30m columns by increasing the carrier gas flow after a modified gel permeation chromatographic cleanup protocol employing cyclohexane/ethyl acetate as eluent
Improved GC/ECNI-MS sensitivity of decabromodiphenyl ether determination on 30m columns by increasing the carrier gas flow after a modified gel permeation chromatographic cleanup protocol employing cyclohexane/ethyl acetate as eluent
复制标题
DOI：
10.1080/03067319.2012.690150
复制
发表时间：
2013-08-01
影响因子：
2.6
通讯作者：
Vetter, Walter
中科院分区：
文献类型：
--
作者：
Bendig, Paul;Vetter, Walter
BDE-209是用作溴化阻燃剂的商用混合物十溴二苯醚的主要成分。由于与高质量有关的困难（热不稳定性和低蒸气压），建议使用较短的气相色谱柱（15米）进行分析，而建议使用较长的色谱柱（30- 50米）来分析其他多溴二苯醚同系物。为了克服多溴联苯醚分析中的这一可观的支出，我们的目的是提高BDE-209分析的灵敏度，气相色谱-电子捕获负离子质谱（GC/ECNI-MS）在30米柱。BDE-209在30 m气相色谱柱上的色谱性能得到改善，在最后一个八溴二苯醚（Br 8DE）同系物洗脱后，将载气流量从最初的1.2mLmin（-1）增加到5或10 mLmin（-1）。在这种高载气流量下，BDE-209的柱停留时间缩短了约25%，峰高增加，从而提高了GC/ECNI-MS在选择离子监测（SIM）模式下的检测限。当这种高流量GC/ECNI-MS-SIM方法应用于沉积物样品时，我们意识到用于去除脂质和/或硫的凝胶渗透色谱法（GPC）对BDE-209的回收率很低。大分子BDE-209洗脱较晚，我们以前的多卤代化合物标准方案仅回收了50%。采用一种收集时间较长的改进的凝胶渗透色谱法，可将凝胶渗透色谱法步骤中BDE-209的回收率提高到约90%。
BDE-209 is the predominant constituent of the commercial mixture decabromodiphenyl ether which is used as brominated flame retardant (BFR). Owing to difficulties associated with the high mass (thermal instability and low vapour pressure), short GC columns (15m) have been suggested for its analysis while longer columns (30-50m) are suggested for other polybrominated diphenyl ether (PBDE) congeners. To overcome this considerable expenditure in the analysis of PBDEs, we aimed at increasing the sensitivity of BDE-209 analysis by gas chromatography coupled with electron-capture negative ion mass spectrometry (GC/ECNI-MS) on a 30m column. The chromatographic performance of BDE-209 on the 30m GC column was improved by increasing the carrier gas flow from initially 1.2mLmin(-1) to 5 or 10mLmin(-1) after the last octabromo diphenyl ether (Br8DE) congener was eluted. With this high carrier gas flow, the column residence time of BDE-209 was shortened by approximate to 25%, the peak height was increased and, consequently, the limit of detection by GC/ECNI-MS in selected ion monitoring (SIM) mode was improved. When this high-flow GC/ECNI-MS-SIM method was applied to a sediment sample, we realized that gel permeation chromatography (GPC) - used for the removal of lipids and/or sulphur - provided low recovery rates for BDE-209. The large molecule BDE-209 eluted late and only 50% was recovered by our previous standard protocol for polyhalogenated compounds. Application of a modified GPC procedure with a longer collection time increased the recovery of BDE-209 in the GPC step to approximate to 90%.