Innovative gas chromatographic determination of formaldehyde by miniaturized extraction and on-fiber derivatization, via SPME and SPME Arrow

Formaldehyde (FA) is a carbonyl compound, ubiquitous in the environment and among the most widespread pollutants: it has exhibited toxic properties and is classified as a human carcinogen. FA is released from several sources, both temporary (e.g., combustion processes) and permanent (e.g., building products). This work proposes an innovative fully-automated application of headspace solid-phase microextraction (SPME) with on-fiber derivatization for the analysis of airborne FA emitted from liquid solutions or solid manufacts, in static mode, via gas chromatography-mass spectrometry. The method was tested in a wide range of airborne FA concentrations, using SPME and SPME Arrow fibers: the inter-day LOD and LOQ for SPME and SPME Arrow were evaluated, resulting in 0.072 and 0.215 ppm and 0.014 and 0.042 ppm, respectively. Moreover, other conventional detectors, such as Electron Capture Detector (ECD), Thermoionic Specific Detector (TSD), Photoionization Detector (PID), and Flame Ionization Detector (FID), were tested to set an analytical method to meet different requirements. The sensitivity and linearity of PID, FID and MS were comparable, while TSD and ECD were not suitable for the developed method, due to issues of response or linearity. MS results to be the most suitable and perfoming detector, however PID and FID result to be cheaper valid alternatives.甲醛（Formaldehyde, FA）是一种羰基化合物，广泛存在于环境中，亦是分布最广泛的污染物之一：该物质具有毒性，已被归类为人类致癌物。甲醛的释放来源多样，涵盖临时性来源（如燃烧过程）与永久性来源（如建筑材料）。本研究提出一种创新性的全自动顶空固相微萃取（headspace solid-phase microextraction, SPME）结合纤维原位衍生化方法，采用静态模式结合气相色谱-质谱联用法，用于分析液体溶液或固体制品释放的空气中甲醛。该方法使用SPME与SPME箭形纤维，在宽范围的空气中甲醛浓度下进行了测试；研究评估了SPME与SPME箭形纤维的日间检出限（Limit of Detection, LOD）与定量限（Limit of Quantitation, LOQ），结果分别为0.072、0.215 ppm与0.014、0.042 ppm。此外，为适配不同分析需求，本研究还测试了电子捕获检测器（Electron Capture Detector, ECD）、热离子特异性检测器（Thermionic Specific Detector, TSD）、光离子化检测器（Photoionization Detector, PID）与火焰离子化检测器（Flame Ionization Detector, FID）等常规检测器，以确立最优分析方法。光离子化检测器、火焰离子化检测器与质谱检测器的灵敏度与线性范围相当，而热离子特异性检测器与电子捕获检测器因响应或线性问题，不适用于本研究开发的方法。质谱检测器被证明是最适用且性能最优的检测器，不过光离子化检测器与火焰离子化检测器亦是经济实惠的有效替代方案。