A Simple Diffuse Reflectance Fourier Transform Infrared Spectroscopic Determination of Sulfur Dioxide in Ambient Air Using Potassium Tetrachloromercurate as the Absorbing Reagent

Abstract

This paper presents development of a simple, rapid, and precise analytical method for determination of sulfur dioxide in ambient air by a gas to solid-phase conversion method. Sulfur dioxide is determined in the form of sulfite (SO32) because the absorbing reagent, potassium tetrachloromercurate (TCM), used in this method absorbs sulfur dioxide from the atmosphere in the form of sulfite. Determination of submicrogram levels of sulfur dioxide was based on the selection of a quantitative analytical peak at 495 cm1 among the 3 observed vibrational peaks for the dichlorosulfitomercurate complex formed after reaction of sulfur dioxide with TCM and measurement of absorbance using diffuse reflectance Fourier transform infrared spectroscopy. The limits of detection and quantification of the method were found to be 0.09 and 0.4 g/g SO32, respectively. The precision in terms of standard deviation and relative standard deviation (RSD) at a level of 2 g SO32/0.1 g KBr for n = 10 was found to be 0.036 g SO32 and 1.8%, respectively. The RSD (n = 10) for determination of sulfur dioxide in ambient air was observed to be in the range of 2.74.2%. The method proposed is time saving and eliminates the slow and cumbersome steps of pH maintenance of the reaction mixture and color formation of the U.S. Environmental Protection Agency recommended West and Gaeke spectrophotometric method and other methods for quantitative determination of sulfur dioxide.

Sources and formation processes of water‐soluble dicarboxylic acids, ω‐oxocarboxylic acids, α‐dicarbonyls, and major ions in summer aerosols from eastern central India

“…Verma et al . [, , ] found high loadings of PM 2.5 (average 239 µg m −3 ) and PM 2.5‐10 aerosols (average 245 µg m −3 ), and gaseous pollutants such as SO 2 (average 95.2 µg m −3 ) and NO 2 (average 115 µg m −3 ) in the atmosphere of Raipur. A cluster of coal‐based industries and growing vehicular population as well as use of firewood and cow dung for domestic cooking are considered as emitters of considerable amount of aerosol particles in Raipur.…”

High Loadings of Water-Soluble Oxalic Acid and Related Compounds in PM2.5 Aerosols in Eastern Central India: Influence of Biomass Burning and Photochemical Processing

“…Biomass burning and combustion of biofuels are identified as the major sources of OAs in eastern central India (Giri et al, 2013;Nirmalkar et al, 2015;Deshmukh et al, 2016). Verma et al (2007Verma et al ( , 2008Verma et al ( , 2010 found high loadings of fine mode aerosols (avg. 239 µg m -3 ) and coarse mode aerosols (avg.…”