Analytical Chemistry Research Group, Department of Physical and Analytical Chemistry, University of Jaén, Campus Las Lagunillas, Edif. B-3, 23071 Jaén, Spain.
Talanta. 2010 Dec 15;83(2):391-9. doi: 10.1016/j.talanta.2010.09.052. Epub 2010 Oct 28.
In this work, a straightforward, reliable and effective automated method has been developed for the direct determination of monoaromatic volatile BTEXS group (namely benzene, toluene, ethylbenzene, o-, m- and p-xylenes, and styrene) in olives and olive oil, based on headspace technique. Separation, identification and quantitation were carried out by headspace-gas chromatography-mass spectrometry (HS-GC-MS) in selected ion monitoring (SIM) mode. Sample pretreatment or clean-up were not necessary (besides olives milling) because the olives and olive oil samples are put directly into an HS vial, automatically processed by HS and then injected in the GC-MS for chromatographic analysis. The chemical and instrumental variables were optimized using spiked olives and olive oil samples at 50 μg kg(-1) of each targeted species. The method was validated to ensure the quality of the results. The precision was satisfactory with relative standard deviations (RSD (%)) in the range 1.6-5.2% and 10.3-14.2% for olive oil and olives, respectively. Limits of detection were in the range 0.1-7.4 and 0.4-4.4 μg kg(-1) for olive oil and olives, respectively. Finally, the proposed method was applied to the analysis of real olives and olive oil samples, finding positives of the studied compounds, with overall BTEXS concentration levels in the range 23-332 μg kg(-1) and 4.2-87 μg kg(-1) for olive oil and olives, respectively.
本工作建立了一种直接测定橄榄和橄榄油中单环芳烃挥发性 BTEX 族（苯、甲苯、乙苯、邻二甲苯、间二甲苯、对二甲苯和苯乙烯）的顶空-气相色谱-质谱（HS-GC-MS）自动化方法。采用选择离子监测（SIM）模式进行分离、鉴定和定量。除橄榄粉碎外，无需进行样品预处理或净化（besides olives milling），因为可以直接将橄榄和橄榄油样品放入顶空瓶中，通过顶空自动处理，然后注入 GC-MS 进行色谱分析。采用加标橄榄和橄榄油样品优化了化学和仪器变量，每种目标物的浓度均为 50μgkg(-1)。对方法进行了验证，以确保结果的质量。该方法的精密度令人满意，橄榄油和橄榄的相对标准偏差（RSD（%））分别在 1.6-5.2%和 10.3-14.2%之间。橄榄油和橄榄的检出限分别在 0.1-7.4 和 0.4-4.4μgkg(-1)之间。最后，将该方法应用于实际橄榄和橄榄油样品的分析，发现研究化合物呈阳性，橄榄油和橄榄中 BTEX 总浓度水平分别在 23-332μgkg(-1)和 4.2-87μgkg(-1)之间。
