An Upgrade of Apparatus and Measurement Systems for Generation of Gaseous Formaldehyde: A Review

Formaldehyde (FA) is ubiquitous in the atmospheric environment. It is generally the dominant atmospheric carbonyl compound. Due to its well-known carcinogenicity, FA is a compound that arises the attention in the scientific community. In studies concerning the toxicological effects of FA on humans, animals, and the environment, testing and calibration of air sampling systems and analytical instruments are pivotal. Therefore, the preparation of controllable standard gaseous atmospheres containing FA at levels known with precision and accuracy is essential. This review summarizes the procedures for generating the FA atmosphere, given that operative solutions have been evolving recently. Furthermore, an overview on the available system to collect and store gaseous standard is reported. The progressively implemented FA generation techniques, together with commercially-available instruments, are herein described, classified, and compared.