Portable Sick House Syndrome Gas Monitoring System Based on Novel Colorimetric Reagents for the Highly Selective and Sensitive Detection of Formaldehyde

Abstract

Formaldehyde (HCHO) emitted from the furniture and the walls in the rooms injures the eyes, nose, and respiratory organs and causes allergies, which is called sick house syndrome. We designed and synthesized novel colorimetric HCHO-sensing molecules (KD-XA01 and KD-XA02) which possess an enaminone structure and developed a hand-held instrument to monitor indoor HCHO gas with the use of KD-XA01. These sensing molecules produced speedy color changes from colorless to yellow under mild conditions, which was caused by the fact that the enaminone structure in the reagent reacts with HCHO to give a lutidine derivative. This reaction took place not only in the solution phase but also in the solid phase (surface of the cellulose paper). To take advantage of this phenomena, a handy and rapid monitoring system has been developed for detecting indoor HCHO gas using a highly sensitive and selective detection tablet constructed from the porous cellulose paper that contains silica gel as an adsorbent, KD-XA01, and phosphoric acid under optimum conditions. This instrument detected the surface color change of the tablet from white to yellow, which was monitored as a function of the intensity of the reflected light illuminated by an LED (475 nm). The response was proportional to the HCHO concentration at a constant sampling time and flow rate; 0.05 ppm HCHO, which is under the standard value set by the World Health Organization, was able to be detected in 5 min. The detection limit was 0.005 ppm. This monitoring system was not interfered by carbonyl compounds such as acetaldehyde and acetone, alcohols, hydrocarbons, and typical gases such as carbon monoxide, carbon dioxide, nitrogen dioxide, etc., which contributes to the measurement of correct HCHO concentrations. It was possible to monitor the HCHO gas in the room of a new apartment and school using this instrument; the response values were in good agreement with those obtained by the standard DNPH method. This highly sensitive, selective, and handy HCHO gas monitor is widely applicable and convenient for users who are not specialists in this field.

Turn on Fluorescent Probes for Selective Targeting of Aldehydes

“…1 H-NMR spectra were referenced to CDCl3 (7.26 ppm). 13 C-NMR spectra were referenced to the CDCl3 (77.00 ppm). 11 B NMR spectra were referenced to BF3.OEt2 (0 ppm).…”

“…As a result, aldehydes are frequently released to the environment, and their presence needs to be monitored [1,2]. Methods to monitor aldehydes include simple colorometric measurements [3][4][5][6][7], and more involved electrochemical, gas chromatography, and chemiluminiscent techniques [8][9][10][11][12][13][14]. One common approach is to detect the product of the reaction of an aldehyde with an aromatic hydrazine.…”

Développement d'un capteur sub-ppb miniaturisé pour la mesure du formaldéhyde gazeux en air intérieur

“…Récemment, Suzuki et al ont montré la formation de dérivés de lutidine à partir de la réaction du 4-amino-4-phenylbut-3-ène-2-one avec le formaldéhyde. Cette réaction peut être réalisée non seulement en solution, mais également sur du papier filtre de cellulose contenant un adsorbant, le silica gel imprégné du réactif [20]. La détection du dérivé de lutidine est réalisée par des mesures de réflectance car le papier filtre n'est pas transparent.…”

vQRS Based on Hybrids of CNT with PMMA-POSS and PS-POSS Copolymers to Reach the Sub-PPM Detection of Ammonia and Formaldehyde at Room Temperature Despite Moisture

“…The limit concentration of short-term exposure to formaldehyde is 0.08 ppm for 30 min [38] and 0.016 ppm for long-term exposure [39]. Different types of sensors have been developed in the literature to detect formaldehyde, such as spectro-colorimetric sensors by Suzuki et al, who made a device using organic molecules that change colour when reacting with CH 2 O [40], or amperometric sensors which take benefit from an enzymatic reaction with formaldehyde molecules, which changes the electrical current in the transducer [41]. Other sensors use metal oxides or have very complex testing setups and generally require high working temperatures, for instance, SiO 2 -NiO-based formaldehyde sensors that operate at 300 • C [42].…”