Department of Instrumental Analysis and Environmental Chemistry, IQOG-CSIC, Juan de Cierva 3, 28006 Madrid, Spain.
J Chromatogr A. 2012 Sep 21;1256:222-31. doi: 10.1016/j.chroma.2012.07.060. Epub 2012 Jul 27.
This study evaluates the feasibility of comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-ToF MS) for the determination of the 15+1 EU PAHs in sediments. Experimental variables affecting the injection, chromatographic separation and analytical detection of the analytes have systematically been optimised. Under finally proposed conditions, a satisfactory resolution among critical pairs/groups of PAHs, including benz[a]anthracene, cyclopenta[cd]pyrene and chrysene, the three benzofluoranthene isomers, indeno[1,2,3-cd]pyrene from dibenz[a,h]anthracene (DahA), and DahA from dibenz[a,c]anthracene, has been achieved using DB-5 × BPX-50 as column combination with a run time of 1 h. The feasibility of the method for the analysis of real-life samples has been demonstrated by accurate determination of relevant target PAHs in the certified harbour sediment BCR-535 (deviations among certified concentration values and those calculated using the proposed method lower than 3%); and by successful application to sediments sampled from a relevant protected area located in the South of Spain. The low methodological limits of detection (LODs) obtained for most of the targeted PAHs (in the 5.7-60 μg/kg range, as calculated for real samples) guarantied accurate quantification of the target compounds at the low levels expected in these types of pristine matrices. The strong retention experienced by the heaviest dibenzopyrene isomers included in the study resulted in relatively high LODs for these analytes; nevertheless, these compounds were detected at concentration levels above the corresponding LOD in some of the analysed sediments. In addition, the enhanced identification power provided by GC × GC-ToF MS for the identification of non-target analytes allowed the tentative identification of a group of polynuclear aromatic thiophenes in some of the test samples. Finally, the potential of the use of normalised bubble plots for the fast screening of the potential PAH sources has been demonstrated.
本研究评估了全面二维气相色谱与飞行时间质谱联用（GC×GC-ToF MS）测定沉积物中 15+1 种欧盟多环芳烃（PAHs）的可行性。系统优化了影响分析物进样、色谱分离和分析检测的实验变量。在最终提出的条件下，采用 DB-5×BPX-50 作为柱组合，运行时间为 1 小时，实现了临界对/PAHs 包括苯并[a]蒽、环戊[cd]芘和䓛、3 种苯并荧蒽异构体、二苯并[a,h]蒽（DahA）中的茚并[1,2,3-cd]芘和苯并[a,c]蒽中的 DahA 之间的良好分离。该方法通过准确测定认证港口沉积物 BCR-535 中相关目标 PAHs（与认证浓度值的偏差低于 3%，采用所提出的方法计算），以及成功应用于位于西班牙南部的相关保护区采集的沉积物，证明了该方法分析实际样品的可行性。大多数目标 PAHs 的方法检出限（LOD）较低（在实际样品中计算为 5.7-60μg/kg 范围内），保证了在这些原始基质中预期的低水平下对目标化合物的准确定量。研究中包含的最重二苯并芘异构体的强保留导致这些分析物的相对较高的 LOD；然而，在一些分析的沉积物中，这些化合物在浓度水平上高于相应的 LOD 时被检测到。此外，GC×GC-ToF MS 为非目标分析物的鉴定提供的增强识别能力允许在一些测试样品中暂定鉴定一组多核芳香硫酚。最后，证明了归一化气泡图用于快速筛选潜在 PAH 来源的潜力。
