Rapid photometric method for the determination of the mass concentration of nitrogen monoxide and nitrogen dioxide

✍ Scribed by K. Suzuki; T. Niimi; N. Yamamoto; M. Shibata; M. Saeki; A. Ono; T. Shirai; S. Yanagisawa

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 609 KB
• Volume: 295
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)80343-9

✦ Synopsis

A novel method has been developed for the photometric determination of nitrogen oxides (NO,; NO and NO, gases). The sample .gas is shaken with an NaOH-alkaline H20, solution in a container so that all the NO, is converted to the NO; form. After decomposition of the H,O, by heating, the colour is developed using naphthylethylenediamine and the absorbance at 545 nm is determined. The reference calibration gases consisting of NO and NO, are determined within 20 min by adding catalase (enzyme) as a rapid decomposition reagent for H,O, instead of the heating decomposition. This simple and rapid photometric method can be used to determine NO, down to 0.5 ppm (v/v) (0.244 mg/m3 as NO,) in the case where a l-l sampling flask is used.