Determination of atmospheric sulfur dioxide without tetrachloromercurate(II) and the mechanism of the Schiff reaction

Abstract

This research was supported by a contract from the Electric Power Research Institute (RP 1112-2).

Fogwater chemistry in an urban atmosphere

“…In the field, samples were stored over ice, then refrigerated when brought back to the laboratory; pH was determined in the field with a Radiometer PHM 80 meter. Sulfite was preserved by addition of CH 20 at pH 4 to form hydroxymethanesulfonic acid (HMSA) [Dasgupta et al, 1980;Fortune and Dellinger, 1982]' 3,5-diacetyl-l,4-dihydrolutidine (DDL) formed by reaction of formaldehyde and acetyl acetone in the presence of NH4 + [Nash, 1953] is stable for at least 7 days [Rietz, 1980]. Sulfite is known to interfere with this reaction [Nash, 1953], but no correction was made.…”

Determinação colorimétrica de metabissulfito

“…De acordo com a literatura, a interação de substâncias sulfuradas como o corante P, ocorre por uma reação de adição, no qual, a dupla ligação quinoidal do corante, sofre uma cisão e incorpora a espécie inorgânica através da ligação com o áto-mo de enxofre no carbono central de P, provocando a descoloração do pigmento [44,45].…”

Low-level atmospheric sulfur dioxide measurement using HPLC/fluorescence detection

“…The use of formaldehyde in the absorbing solution was originally intended to assist in the trapping and stabilization of the S(IV) against oxidation through the formation of hydroxymethanesulfonic acid (HMSA). This adduct has been shown to stabilize sulfite against oxidation in cloud droplets and absorbing solutions (Dasgupta et al, 1980;Munger et al, 1984). However, in an effort to lower system blank levels, it was noted that the formaldehyde appears to remain effective at protecting S(IV) at levels below which HMSA formation should be important.…”