Laboratory of Aquatic Chemistry, School of Environmental Engineering, Polytechnioupolis, Technical University of Crete, GR-73100, Chania, Crete, Greece.
Laboratory of Aquatic Chemistry, School of Environmental Engineering, Polytechnioupolis, Technical University of Crete, GR-73100, Chania, Crete, Greece.
J Chromatogr A. 2019 Sep 27;1602:142-149. doi: 10.1016/j.chroma.2019.03.047. Epub 2019 Mar 23.
Headspace solid-phase microextraction (HSSPME) is a widespread technique used to extract trace amounts of haloanisoles from wine samples. A major challenge to overcome is the high ethanol content in wines that affects the solubilities of haloanisoles and reduces their headspace abundance. To overcome this obstacle and meet sensitivity requirements, reported HSSPME procedures typically suggest heating the wine samples and/or sampling for extended times. The present work proposes the use of vacuum-assisted HSSPME (Vac-HSSPME) to accelerate the extraction kinetics whilst sampling at room temperature. Although ethanol affected the physico-chemical properties of the target analytes, these changes were not sufficient to prevent the positive effect of vacuum on HSSPME sampling. To demonstrate the benefits of adopting the vacuum approach, Vac-HSSPME and regular HSSPME methods were independently optimized and the results were compared at all times. The effect of ethanol under each pressure condition was also discussed. Under the optimum conditions found, Vac-HSSPME sampling for 30 min at room temperature at 25 °C yielded lower detection limits (0.13 to 0.19 ng L) than those obtained with regular HSSPME sampling for 30 min at 55 °C (0.26 to 0.76 ng L). The proposed Vac-HSSPME method was successfully applied to quantify haloanisoles in bottled red wines and a discussion on the effect of wine volatiles was included. The standard addition method was used to minimize matrix effects. The increase in total pressure due to the presence of ethanol and other volatile wine components did not reduce the positive effect of vacuum on HSSPME. Nonetheless, in accordance to past HSSPME methods, the limits of detection and quantification were affected due to the noise level increase and analyte interaction with matrix. The proposed Vac-HSSPME procedure was applied to twelve bottled red wines and one sample was found positive on 2,4,6-trichloronanisole.
顶空固相微萃取（HSSPME）是一种广泛使用的技术，用于从葡萄酒样品中提取痕量的卤代苯甲醚。需要克服的一个主要挑战是葡萄酒中的高乙醇含量会影响卤代苯甲醚的溶解度并降低其顶空丰度。为了克服这一障碍并满足灵敏度要求，已报道的 HSSPME 程序通常建议加热葡萄酒样品和/或延长采样时间。本工作提出使用真空辅助顶空固相微萃取（Vac-HSSPME）在室温下加速萃取动力学的同时进行采样。尽管乙醇会影响目标分析物的物理化学性质，但这些变化不足以阻止真空对 HSSPME 采样的积极影响。为了证明采用真空方法的好处，独立优化了 Vac-HSSPME 和常规 HSSPME 方法，并始终比较结果。还讨论了每种压力条件下乙醇的影响。在所找到的最佳条件下，在 25°C 下室温下真空辅助顶空固相微萃取采样 30 分钟，比在 55°C 下常规顶空固相微萃取采样 30 分钟获得更低的检测限（0.13 至 0.19ng L）（0.26 至 0.76ng L）。所提出的 Vac-HSSPME 方法成功地用于定量瓶装红葡萄酒中的卤代苯甲醚，并讨论了葡萄酒挥发性物质的影响。采用标准加入法以最小化基质效应。由于乙醇和其他挥发性葡萄酒成分的存在而导致的总压力增加并没有降低真空对 HSSPME 的积极影响。尽管如此，根据过去的 HSSPME 方法，由于噪声水平的增加和分析物与基质的相互作用，检测限和定量限受到影响。所提出的 Vac-HSSPME 程序应用于十二种瓶装红葡萄酒，一种样品在 2,4,6-三氯代苯甲醚上呈阳性。
