Environmental Science and Engineering Ph.D Program, The University of Texas at El Paso, 500 W. University Ave., El Paso, TX 79968-0513, USA.
J Chromatogr A. 2010 Oct 29;1217(44):6816-23. doi: 10.1016/j.chroma.2010.08.055. Epub 2010 Sep 28.
A simple, cost effective, and yet sensitive sample preparation technique was investigated for determining Polycyclic Aromatic Hydrocarbons (PAHs) in solid samples. The method comprises ultrasonic extraction, Stir Bar Sorptive Extraction (SBSE), and thermal desorption-gas chromatography-mass spectrometry to increase analytical capacity in laboratories. This method required no clean-up, satisfied PAHs recovery, and significantly advances cost performance over conventional extraction methods, such as Soxhlet and Microwave Assisted Extraction (MAE). This study evaluated three operational parameters for ultrasonic extraction: solvent composition, extraction time, and sample load. A standard material, SRM 1649 a (urban dust), was used as the solid sample matrix, and 12 priority PAHs on the US Environmental Protection Agency (US EPA) list were analyzed. Combination of non-polar and polar solvents ameliorated extraction efficiency. Acetone/hexane mixtures of 2:3 and 1:1 (v/v) gave the most satisfactory results: recoveries ranged from 63.3% to 122%. Single composition solvents (methanol, hexane, and dichloromethane) showed fewer recoveries. Comparing 20 min with 60 min sonication, longer sonication diminished extraction efficiencies in general. Furthermore, sample load became a critical factor in certain solvent systems, particularly MeOH. MAE was also compared to the ultrasonic extraction, and results determined that the 20-min ultrasonic extraction using acetone/hexane (2:3, v/v) was as potent as MAE. The SBSE method using 20 mL of 30% alcohol-fortified solution rendered a limit of detection ranging from 1.7 to 32 ng L(-1) and a limit of quantitation ranging from 5.8 to 110 ng L(-1) for the 16 US EPA PAHs.
研究了一种简单、经济且灵敏的样品制备技术，用于测定固体样品中的多环芳烃（PAHs）。该方法包括超声提取、搅拌棒吸附萃取（SBSE）和热解吸-气相色谱-质谱联用，以提高实验室的分析能力。该方法无需净化，满足 PAHs 的回收率要求，并且与传统的提取方法（如索氏提取和微波辅助提取（MAE））相比，具有显著的成本效益优势。本研究评估了超声提取的三个操作参数：溶剂组成、提取时间和样品负载。使用标准物质 SRM 1649 a（城市灰尘）作为固体样品基质，分析了美国环保署（US EPA）优先控制的 12 种 PAHs。非极性和极性溶剂的组合改善了提取效率。2:3 和 1:1（v/v）的丙酮/己烷混合物得到了最令人满意的结果：回收率范围为 63.3%至 122%。单一组成的溶剂（甲醇、己烷和二氯甲烷）显示出较少的回收率。与 60 分钟超声相比，20 分钟的超声时间通常会降低提取效率。此外，样品负载在某些溶剂系统中成为一个关键因素，特别是在甲醇中。还将 MAE 与超声提取进行了比较，结果表明，使用丙酮/己烷（2:3，v/v）的 20 分钟超声提取与 MAE 一样有效。使用 20 mL 30%酒精强化溶液的 SBSE 方法的检出限范围为 1.7 至 32 ng L(-1)，定量限范围为 5.8 至 110 ng L(-1)，适用于 16 种美国环保署 PAHs。
