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，属于分布最广的污染物之一，具有毒性并被归类为人类致癌物。其排放来源多样，涵盖临时来源（如燃烧过程）与永久来源（如建筑制品）。本研究提出一种创新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的方法，可在静态模式下通过气相色谱-质谱联用（gas chromatography-mass spectrometry）分析液态溶液或固态制品释放的空气中甲醛。本研究分别采用SPME与SPME Arrow纤维，在较宽的空气中甲醛浓度范围内对该方法进行了测试；评估了SPME及SPME Arrow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，以及0.014、0.042 ppm。此外，为构建适配不同分析需求的分析方法，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）及火焰离子化检测器（Flame Ionization Detector, FID）等常规检测器。PID、FID与MS的灵敏度及线性表现相当，而TSD与ECD因响应特性或线性问题，不适用于本研究所开发的方法。MS是适用性与性能最优的检测器，不过PID和FID亦是性价比较高的可行替代方案。