Schanzmann Hannah, Gaar Selina, Keip Svenja, Telgheder Ursula, Sielemann Stefanie
Laboratory of Applied Instrumental Analytical Chemistry, Hamm-Lippstadt University of Applied Sciences, Hamm, 59063, Germany.
Faculty of Chemistry, Instrumental Analytical Chemistry, University of Duisburg-Essen, Essen, 45141, Germany.
Anal Bioanal Chem. 2025 Jun 3. doi: 10.1007/s00216-025-05933-w.
Accurate and reproducible quantification of volatile organic compounds (VOCs) is essential in environmental monitoring, clinical diagnostics, and quality control. Thermal desorption gas chromatography (TD-GC) is widely used for VOC analysis, often coupled with mass spectrometry (MS) for reliable identification. Ion mobility spectrometry (IMS) has gained attention for its high sensitivity and rapid detection. While GC-IMS and GC-MS are well established, TD-GC coupled to both IMS and MS has not been systematically investigated. This study presents a comprehensive assessment of a TD-GC-MS-IMS system, combining the strengths of both detectors. A mobile flow- and temperature-controlled sampling unit for TD tubes was developed for standardized applications, designed to introduce both gaseous and liquid samples. The long-term stability of TD-GC-IMS was assessed over 16 months with 156 measurement days using ketones. Relative standard deviations for signal intensities ranged from 3% to 13%, retention time deviations from 0.10% to 0.22%, and drift time deviations from 0.49% to 0.51%. Comparative evaluation showed IMS was approximately ten times more sensitive than MS, achieving limits of detections in the picogram/tube range. In contrast, MS exhibited a broader linear range, maintaining linearity over three orders of magnitude (up to 1000 ng/tube), while IMS retained linearity for one order of magnitude (e.g., 0.1 to 1 ng/tube for pentanal) before transitioning into a logarithmic response. To improve IMS quantification, a linearization strategy extended the calibration range from one to two orders of magnitude. These findings establish a standardized TD-GC-MS-IMS framework, improving reproducibility and comparability for clinical, environmental, and industrial VOC analysis.
在环境监测、临床诊断和质量控制中，准确且可重复地定量分析挥发性有机化合物（VOCs）至关重要。热脱附气相色谱法（TD-GC）广泛用于VOC分析，通常与质谱法（MS）联用以便进行可靠的鉴定。离子迁移谱（IMS）因其高灵敏度和快速检测而受到关注。虽然气相色谱-离子迁移谱（GC-IMS）和气相色谱-质谱联用（GC-MS）已得到广泛应用，但将TD-GC与IMS和MS联用尚未得到系统研究。本研究对结合了两种检测器优势建立的TD-GC-MS-IMS系统进行全面评估。开发了一种用于TD管的流动和温度可控的移动采样单元，用于标准化应用，该单元设计用于引入气态和液态样品。使用酮类物质在16个月内的156个测量日评估了TD-GC-IMS的长期稳定性。信号强度的相对标准偏差范围为3%至13%，保留时间偏差为0.10%至0.22%，漂移时间偏差为0.49%至0.51%。对比评估表明，IMS的灵敏度约为MS的十倍，检测限可达皮克/管范围。相比之下，MS表现出更宽的线性范围，在三个数量级（高达1000 ng/管）内保持线性，而IMS在转变为对数响应之前仅在一个数量级内保持线性（例如，戊醛为0.1至1 ng/管）。为了改进IMS定量，一种线性化策略将校准范围从一个数量级扩展到两个数量级。这些发现建立了一个标准化的TD-GC-MS-IMS框架，提高了临床、环境和工业VOC分析的重现性和可比性。
