کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10179879 1310518 2016 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Diazo-coupling spectrophotometric determination of nitrogen oxides in the air
ترجمه فارسی عنوان
تعیین ایزاییت نیتروژن در هوا با استفاده از ضریب همبستگی اسپکتروفتومتری
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علم هواشناسی
چکیده انگلیسی
A new accurate, sensitive, rapid and convenient measurement for the determination of nitrogen oxides in the air was established. After being oxidized by chromium trioxide (CrO3), nitrogen oxides in the air existed in the form of NO2, then forming nitrite and nitrate after being absorbed by the alkaline aqueous solution. Under acidic condition, the diazo reaction is specific to the nitrite and primary aromatic amine. In this paper, the structure of diazo and coupling compounds were selected and tested through the experiments. The relationship between the azo compound's molecular structure and the sensitivity of the method as well as the electronic flow direction in the conjugated system of azo compounds were studied. A theory that conjugated system's electron cloud in azo compound's molecule flowed from coupling compounds to diazo compounds through nitrogen and nitrogen double bond was proposed. This theory had a guiding function for exploiting highly sensitive chromogenic agents. Furthermore, the conditions and methods of diazo reaction and coupling chromogenic reaction were investigated. A spectrophotometry that p-aminobenzenesulfonic acid as diazo compound and 2-amino-5-naphthol-7-sulfonic acid (J acid) as coupling compound for the determination of nitrogen oxides in the air was established. The maximum absorption wavelength of p-aminobenzenesulfonic acid-J acid azo compound was at 480 nm. And the molar absorptivity was 4.01 × 104 L mol−1 cm−1 with recovery of 98.5%-100.9% and R.S.D. of 1.82%. In addition, the determination limit of measurement was 0.017 mg m−3 nitrogen oxides and the determination range was 0.027-2.0 mg m−3 nitrogen oxides. This method can be easily applied to the determination of the nitrogen oxides in the air.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Atmospheric Pollution Research - Volume 7, Issue 2, March 2016, Pages 333-338
نویسندگان
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