Exposure to airborne formaldehyde: Sampling and analytical methods—A review

Air monitoring is the quantitative-qualitative assessment of the extent of pollutants. It is performed to ensure compliance with legislation and to evaluate control measures and mitigation solutions. There are numerous approaches to measure airborne formaldehyde (FA), ranging from passive sampling techniques to remote sensing devices. Research of sampling procedures and analytical methods was performed in a scientific database and on the web to offer a scenario of the devices and techniques that can be used to assess FA exposure. Moreover, in the design of FA assessment, some crucial aspects were considered, such as standard atmosphere generation for devices calibration. This review summarizes the tools and basics used in FA air monitoring, useful to organize a functional monitoring strategy for assessment of FA concentration levels. An insight into the sampling and analysis of FA is provided. Recent advances in solid sorbent technology allow analysts to use these devices coupled to chromatographic instruments. A comparison of the strengths and weaknesses of analytical methods (gas-/liquid-chromatography coupled with mass spectrometry or UV detection, chromogenic, colorimetric, electrochemical determination) and sampling devices (impregnated papers, solid sorbents, liquid sorbents, bubblers, impingers, micro-impingers, denuder samplers, sealed bags, canisters) methods are illustrated. This survey found that a monitoring strategy should be planned considering the most appropriate methodology in terms of costs and practicability. Therefore, it is necessary to know the aspects that can make the chosen strategy suitable and valid for the exposure scenario under investigation.