Development of a detection tablet for a portable NO2 monitoring system.
We have already developed a HCHO monitoring system which is called FP-30. In this experiment, we have developed a NO(2) detection tablet which can be used by the monitoring system. The detection tablet for the NO(2) was constructed with the sensing paper: porous cellulose paper that contains silica gel as an adsorbent, N-1-naphthylethylenediamine dihydrochloride (NED), and glycerin. The NO(2) in sample gas was blown over and adsorbed on the surface of the sensing paper. Then the NO(2) reacted with NED, producing a yellow compound. The coloring reaction took place on the surface of the sensing paper. The degree of color change of paper from white to yellow was monitored as a function of the intensity of the reflected light (lambda = 475 nm) of an LED. The detection limit was 0.01 ppm when the sampling time was 30 min, and the flow rate of sample gas was 250 ml/min. This sensing paper process was not interfered with by acetaldehyde, acetone, alcohols, hydrocarbons, carbon monoxide or carbon dioxide. The NO(2) concentrations in the rooms of a house or school were monitored using this monitoring system and the standard chemiluminescence method. The concentrations of NO(2) monitored by both methods were within 18% of the average. This highly sensitive, selective, and handy NO(2) gas monitoring system will be widely applicable and convenient for users who are not specialists in this field.
Ishiguro
Gaku
G
Riken Keiki Co., Ltd., Tokyo, Japan.
Kawabe
Tetsuya
T
Nakano
Nobuo
N
Nagashima
Kunio
K
D000393:Air Pollutants / Q000032:analysis*; D002138:Calibration; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D007202:Indicators and Reagents; D009585:Nitrogen Dioxide / Q000032:analysis*; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
D000393:Air Pollutants; D007202:Indicators and Reagents; D009585:Nitrogen Dioxide