Comparison of Mass Concentrations of SO sub(2) Determined in Air by Two Different Methods

Sulfur dioxide was determined in parallel 24-h sampling experiments at a suburban residential area in the UK. The Standard British Method (SBM) uses absorption of SO sub(2) in a 1% solution of hydrogen peroxide. The tetrachloromercurate-pararosaniline (TCM) method employs absorption of SO sub(2) in tetrachloromercurate solution. Experiments conducted over an 8-yr period revealed that both methods were sufficient for determining SO sub(2) concentrations in an urban area. The mean annual mass concentrations of SO sub(2) were slightly lower with the TCM method than with the SBM.