Laboratori del Centre de Medi Ambient, Universitat Politècnica de Catalunya (LCMA-UPC), Avda. Diagonal, 647. E 08028, Barcelona, Spain.
Talanta. 2011 Jul 15;85(1):662-72. doi: 10.1016/j.talanta.2011.04.043. Epub 2011 Apr 21.
A simple comparison is made to evaluate the relative performance of active and passive sampling methods for the analysis of volatile organic compounds (VOCs) in ambient air. The active sampling is done through a multi-sorbent bed tube (Carbotrap, Carbopack X, Carboxen 569) created in our laboratory and the passive sampling through the Radiello(®) diffusive sampler specified for thermal desorption (filled with Carbograph 4). Daily duplicate samples of multi-sorbent bed tubes were taken during a period of 14 days. During the same period of time, quadruplicate samples of Radiello(®) tubes were taken during 3 days, 4 days, 7 days and 14 days. The sampling was carried out indoors during the months of February and March 2010 and outdoors during the month of July 2010 in La Canonja (Tarragona, Spain). The analysis was performed by automatic thermal desorption (ATD) coupled with capillary gas chromatography (GC)/mass spectrometry detector (MSD). The analytical performance of the two sampling approaches was evaluated by describing several quality assurance parameters. The results show that the analytical performances of the methodologies studied are quite similar. They display low limits of detection, good precision, accuracy and desorption efficiency, and low levels of breakthrough for multi-sorbent bed tubes. However, the two monitoring methods produced varying air-borne concentration data for most of the studied compounds, and the Radiello(®) samplers generally gave higher results. Sampling rates (Q(k)) were determined experimentally, and their values were higher than those supplied by the producer. As the experimental calculation of Q(k) values is generally carried out by the suppliers in exposure chambers with only the target compounds present in the air samples, as well as in concentrations dissimilar to those found in ambient air, the use of constant settled Q(k) can lead to inaccurate results in complex samples.
为了评估主动和被动采样方法在分析环境空气中挥发性有机化合物（VOC）方面的相对性能，进行了简单的比较。主动采样是通过我们实验室中创建的多吸附剂床管（Carbotrap、Carbopack X、Carboxen 569）进行的，而被动采样是通过Radiello（®）指定用于热解吸的扩散采样器进行的（填充有 Carbograph 4）。在 14 天的时间内，每天采集多吸附剂床管的双份重复样品。在同一时期，Radiello（®）管的四份样品在 3 天、4 天、7 天和 14 天内采集。采样在 2010 年 2 月和 3 月的室内进行，在 2010 年 7 月的室外进行，地点在西班牙的拉康尼亚（塔拉戈纳）。分析通过自动热解吸（ATD）与毛细管气相色谱（GC）/质谱检测器（MSD）联用进行。通过描述几个质量保证参数来评估两种采样方法的分析性能。结果表明，所研究的两种采样方法的分析性能非常相似。它们具有较低的检测限、良好的精密度、准确度和解吸效率，以及多吸附剂床管的低穿透水平。然而，对于大多数研究化合物，这两种监测方法产生了不同的空气浓度数据，并且 Radiello（®）采样器通常给出了更高的结果。采样速率（Q（k））通过实验确定，其值高于生产商提供的值。由于供应商通常在暴露室内用仅存在于空气样品中的目标化合物以及与环境空气中发现的浓度不同的化合物来进行 Q（k）值的实验计算，因此使用恒定的 settled Q（k）可能会导致在复杂样品中得出不准确的结果。
