Otro
Método colorimétrico para determinação de dióxido de nitrogênio atmosférico com preconcentração em coluna de c-18
Registro en:
Química Nova. Sociedade Brasileira de Química, v. 25, n. 3, p. 352-357, 2002.
0100-4042
10.1590/S0100-40422002000300003
S0100-40422002000300003
S0100-40422002000300003.pdf
Autor
Ugucione, Cássia
Gomes Neto, José de Anchieta
Cardoso, Arnaldo Alves
Resumen
An alternative analytical method for nitrogen dioxide (NO2) in atmosphere was developed. The collection of NO2 is performed by a Sep-Pack C-18 cartridge impregnated with 11% (v/v) of triethanolamine plus 3,6 % (v/v) of ethylene glycol plus 25 % (v/v) of acetone combined solution. When the impregnating is used, NO2 is collected with good repeatibility (CV = 3,3 %). The NO2 absorbed in the sampler was stripped from the sorbent with a methanol 5% (v/v) aqueous solution and was determined by colorimetry as nitrite by using the Griess-Saltzman reagent. The detection limit of 1,4 ppb for 60 min sampling at 0,5 L min-1 flow rate was obtained. Preparation and conditioning procedures for TEA-C-18 cartridge, sampling flow rate, absorption capacity and interference of other species are discussed. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)