Suzuki Yoshio, Nakano Nobuo, Suzuki Koji
Collaboration of Regional Entities for the Advancement of Technological Excellence, Kanagawa Academy of Science and Technology, 3-2-1 Sakato, Takatsu-ku, Kawasaki, Kanagawa 213-0012, Japan.
Environ Sci Technol. 2003 Dec 15;37(24):5695-700. doi: 10.1021/es0305050.
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.
房间内家具和墙壁释放出的甲醛（HCHO）会损害眼睛、鼻子和呼吸器官并引发过敏，这就是所谓的“病态建筑综合症”。我们设计并合成了具有烯胺酮结构的新型比色甲醛传感分子（KD-XA01和KD-XA02），并开发了一种手持式仪器，利用KD-XA01来监测室内甲醛气体。这些传感分子在温和条件下能迅速发生颜色变化，从无色变为黄色，这是因为试剂中的烯胺酮结构与甲醛反应生成了一种卢剔啶衍生物。该反应不仅在溶液相中发生，也在固相中（纤维素纸表面）发生。为利用这一现象，我们开发了一种便捷快速的监测系统，用于检测室内甲醛气体，该系统使用了一种高灵敏度和选择性的检测片剂，该片剂由含有硅胶作为吸附剂、KD-XA01和磷酸的多孔纤维素纸在最佳条件下构建而成。该仪器检测片剂表面颜色从白色变为黄色的变化，并将其作为由发光二极管（475纳米）照射的反射光强度的函数进行监测。在恒定的采样时间和流速下，响应与甲醛浓度成正比；能够在5分钟内检测到0.05 ppm的甲醛，这一浓度低于世界卫生组织设定的标准值。检测限为0.005 ppm。该监测系统不受乙醛、丙酮等羰基化合物、醇类、碳氢化合物以及一氧化碳（CO）、二氧化碳（CO₂）、二氧化氮（NO₂）等典型气体的干扰，这有助于准确测量甲醛浓度。使用该仪器可以监测新公寓房间和学校内的甲醛气体；响应值与通过标准2,4-二硝基苯肼（DNPH）法获得的值高度一致。这种高灵敏度、选择性和便捷的甲醛气体监测仪广泛适用，对于该领域非专业的用户来说非常方便。
